4604: Bug 1583870 - Migrate build tasks for PRs and pushes r=JohanLorenzo a=JohanLorenzo



Co-authored-by: Johan Lorenzo <jlorenzo@mozilla.com>

4608: Bug 1583870 - Remove snapshot tasks which should not have been there r=JohanLorenzo a=JohanLorenzo



Co-authored-by: Johan Lorenzo <jlorenzo@mozilla.com>

4609: Fix find in page not working with fresh install r=csadilek a=VMadalin

### Description
Fixed issue: https://github.com/mozilla-mobile/reference-browser/issues/915

The `engineSession` is null on `FindInPageInteractor` because the `bind()` method set it as null via `session.engineState.engineSession`. 
<img width="752" alt="Screenshot 2019-10-02 at 08 25 39" src="https://user-images.githubusercontent.com/18151158/66025739-799e8e00-e4f7-11e9-944d-73ab86d45485.png">

Finally and after deep research I discover the problem is related with the tabs, when `EngineStateReducer.reduce()` is called for the first time no one has add the new tab created and without it it's imposible to propagate the `GeckoEngineSession` to the `BrowserState`

```
2019-10-02 17:50:58.885 8585-9964/org.mozilla.samples.browser: UnlinkEngineSessionAction
2019-10-02 17:50:58.891 8585-9964/org.mozilla.samples.browser: LinkEngineSessionAction
2019-10-02 17:50:58.919 8585-9964/org.mozilla.samples.browser: AddTabAction  // after link
```

### Pull Request checklist
<!-- Before submitting the PR, please address each item -->
- [x] **Quality**: This PR builds and passes detekt/ktlint checks (A pre-push hook is recommended)
- [x] **Tests**: This PR includes thorough tests or an explanation of why it does not
- [ ] **Changelog**: This PR includes [a changelog entry](https://github.com/mozilla-mobile/android-components/blob/master/docs/changelog.md) or does not need one
- [x] **Accessibility**: The code in this PR follows [accessibility best practices](https://github.com/mozilla-mobile/shared-docs/blob/master/android/accessibility_guide.md) or does not include any user facing features

### After merge
- [ ] **Milestone**: Make sure issues closed by this pull request are added to the [milestone](https://github.com/mozilla-mobile/android-components/milestones) of the version currently in development.
- [ ] **Breaking Changes**: If this is a breaking change, please push a draft PR on [Reference Browser](https://github.com/mozilla-mobile/reference-browser

) to address the breaking issues.


Co-authored-by: Madalin Valceleanu <devmobile@vmadalin.com>

4555: Closes #4535: Integrate setEnhancedTrackingProtectionLevel geckoView api. r=csadilek a=Amejia481



Co-authored-by: Arturo Mejia <arturomejiamarmol@gmail.com>

4600:  Closes #4289: Migrate feature-prompts to use browser-state  r=pocmo a=csadilek

This migrates our feature-prompts module to browser-state. 

@pocmo I ended up introducing `Flow.ifAnyChanged` here because returning a `Pair` or other data class instance from `ifChanged` wouldn't have worked. We're comparing for reference equality in `ifChanged` so returning a new `Pair` would always indicate change and forward the value. 

The `ifChanged` block would have to get quite complicated. We'd have to return a different instance only if changed but then we're doing all the work in the feature module and the API doesn't help us. With `ifAnyChanged` this looks quite nice and we can refine the API more later.

Most other changes are in the unit tests. I also did a round of manual testing, thanks to @Amejia481 for sending me lots of links to test :). 

I'll put up PRs for R-B and Fenix, once this one is approved.

Co-authored-by: Christian Sadilek <christian.sadilek@gmail.com>

4579: mozilla-mobile/fenix#5592 - enable private browsing for custom tabs r=NotWoods a=mohamediburan

This PR enables private mode for custom tabs (see issue mozilla-mobile/fenix#5592) where it will not track history. This PR already passed all the tests and I checked tabIntentProcessor.kt file for sample tests. So, I can update test for this. but, I didn't find any tests for verifying whether it a private or normal tab. If I need to write test cases for this, please let me know.



4594: Prevent multiple browser menus r=pocmo a=Mugurell



4607:  GeckoView update (nightly) (20191002-150346) r=pocmo a=MickeyMoz



Co-authored-by: Mohamed Iburan <mdiburan@gmail.com>
Co-authored-by: Petru Lingurar <petru.lingurar@softvision.ro>
Co-authored-by: MickeyMoz <sebastian@mozilla.com>

4595: 1585021: Fix ordering of events at startup to prevent negative timestamps r=mdboom a=mdboom

See https://bugzilla.mozilla.org/show_bug.cgi?id=1585021

 for context.



4601:  GeckoView update (nightly) (20191002-085658) r=pocmo a=MickeyMoz



4602:  Docs update (20191002-121249) [ci skip] r=pocmo a=MickeyMoz



4603: Bump the glean_parser required version to 1.8.3 r=Dexterp37 a=Dexterp37

This is needed in order to fix MemoryDistributionMetricType(s).




Co-authored-by: Michael Droettboom <mdboom@gmail.com>
Co-authored-by: MickeyMoz <sebastian@mozilla.com>
Co-authored-by: Alessio Placitelli <alessio.placitelli@gmail.com>

4605: Bug 1583870 - Fix snapshot decision task r=pocmo a=JohanLorenzo



Co-authored-by: Johan Lorenzo <jlorenzo@mozilla.com>

This is needed in order to fix MemoryDistributionMetricType(s).

4592: Bug 1583870 - Migrate lint and ui-test tasks r=JohanLorenzo a=JohanLorenzo



Co-authored-by: Johan Lorenzo <jlorenzo@mozilla.com>

Added a simple check for if the menu is showing depending on which we will know
to either dismiss it or construct and show a new one.

4591: Bug 1583870 - Fix cron/bors variables r=JohanLorenzo a=JohanLorenzo



Co-authored-by: Johan Lorenzo <jlorenzo@mozilla.com>

4538: Fixes #4414 - Disable disk cache for PWA icons r=jonalmeida a=NotWoods

For some reason the disk cache causes problems with loading PWA icons from some sites like proxx.app and twitter.com. For now, let's remove it and we can add it back in later through #3799.



Co-authored-by: Tiger Oakes <toakes@mozilla.com>

4541: Bug 1583870 - Start converting a-c to taskgraph r=pocmo a=JohanLorenzo



Co-authored-by: Johan Lorenzo <jlorenzo@mozilla.com>