Issue #305: video pauses when app bar scrolls off screen

[mcomella]

RCA: setting an elevation on the AppBar will pause playing WebView videos when the AppBar is scrolled off-screen for an unknown reason. See XML for details.

@brampitoyo @athomasmoz FYI: one side-effect of this change is that the AppBar displays a shadow on the initial homescreen (i.e. only on cold start) on all devices: I didn't feel it was worth the complexity to selectively enable this fix on different devices to avoid this on all devices but the ES5. Here's a screenshot:

Pull Request checklist

• [x] This PR includes thorough tests or an explanation of why it does not
  • All UX change
• [x] This PR includes a CHANGELOG entry or does not need one
• [x] The UI tests are passing after this PR (./gradlew connectedAmazonWebViewDebugAndroidTest)
• [x] I have considered adding QA labels on the associated issue (not this PR; qa-ready or qa-denied)

[mcomella]

CI failed with lint error, looking into a fix:

   /home/travis/build/mozilla-mobile/firefox-echo-show/app/src/main/java/org/mozilla/focus/toolbar/ToolbarIntegration.kt:162: Error: Expected resource of type drawable [ResourceType]

              AppCompatResources.getDrawable(context, drawableId)!!

[brampitoyo]

@mcomella Issue noted. Do we expect the shadow to appear in all devices going forward? If it affects everybody on nearly every launch, it may be worth fixing. Otherwise, I’d consider it a corner case.

[mcomella]

@mcomella Issue noted. Do we expect the shadow to appear in all devices going forward? If it affects everybody on nearly every launch, it may be worth fixing. Otherwise, I’d consider it a corner case.

Yes, it's expected to affect all users. However, I thought of a simple fix so I'm trying it out now.

[mcomella]

Yes, it's expected to affect all users. However, I thought of a simple fix so I'm trying it out now.

The simple fix is going in https://github.com/mozilla-mobile/firefox-echo-show/issues/314