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* Add a basic main activity that shows some info about the webview
  package in use:
  - WebView package name.
  - WebView version name and code.
  - Device build fingerprint.
* Use activity action bar menu to provide navigation options to other
  existing webview dev UIs, Crash UI in this case.
* Use device default theme for more natural look.
* Copy info content to clipboard when tapped.
* Add the shared navigation menu to Crash UI, and show the refresh
  option outside the menu "ifRoom" available.
* Set DevUI activities launch mode to be "singleTask" and "SingleTop"
  for more intuitive navigation.

Fixed: 981154
Test: Manually verify it on SystemWebView and Trichrome on Android Q and MonoChrome on Android P
Change-Id: I61dbcbb714b1b5a18cc4a61a894257a77bcd20b6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1877267
Commit-Queue: Hazem Ashmawy <hazems@chromium.org>
Auto-Submit: Hazem Ashmawy <hazems@chromium.org>
Reviewed-by: Richard Coles <torne@chromium.org>
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710195}