CB-8112 Turn off mediaPlaybackRequiresUserGesture

Conflicts:

	framework/src/org/apache/cordova/CordovaWebView.java
CB-8119 Restart adb when we detect it's hung
Revert Gradle distributionUrlRegex cleanup.

This reverts commit 75a0a6752a77e2e0f491ae4de7137f5163c7a4bd.
CB-8143: Use the correct Android Gradle plugin for the installed Gradle version
CB-3679 Move splashscreen logic into splashscreen plugin

Tried as hard as possible for this not to be a breaking change (all
symbols were preserved). Planning to remove delegating symbols in 4.0.x
though.

Also for backwards compatability - a copy of the plugin is bundled. It
will likewise be removed in 4.0.x
Add a section for plugin extensions

The build.gradle will apply gradle srcipte from plugin extension
When install the plugin with "gradleReference" framework.
The gradle can set ext.multiarch=true to support multiple APKs by
default, so add this section in here.
CB-7881 Android tooling shouldn't lock application directory

Close #130
Close #137 (already merged).
Close #126 (not-a-problem)
CB-8147 Have corodva/build warn about unrecognized flags rather than fail

Close #127
Fix syntax error in 3aca14d53068
CB-8079 Use activity class package name, but fallback to application
package name when looking for splash screen drawable

Close #136