[Android Extension] Fix Activity leaking caused by DeviceCapabilities extension

The static XWalkMediaCodec singleton instance indirectly holds a
reference to Activity via XWalkExtensionManager, it would prevent the
Activity object from GCed and then leak it and all its resources.

BUG=https://crosswalk-project.org/jira/browse/XWALK-2000
[Android] Add a tracing tool for XWalk

It's a wrapper of adb_profile_chrome.py from upstream to support tracing in XWalkRuntimeClientEmbeddedShell.

BUG=XWALK-1977
Merge pull request #2128 from hmin/activity-leak

[Android Extension] Fix Activity leaking caused by DeviceCapabilities ex...
Merge pull request #2126 from kurli/profile

[Android] Add a tracing tool for XWalk
[Android] Refine the key event dispatch for xwalkview

Including following changes:
1. Hook shouldOverrideKeyEvent and onUnhandledKeyEvent into
   content layer correctly.
2. Move the key event handling in xwalkview into dispatchKeyEvent.

After change the process of key dispatch in xwalkview will be:
  Activity.dispatchKeyEvent
  -> XWalkClient.shouldOverrideKeyevent
        <if shouldOverrideKeyevent returns true>
     -> XWalkView.dispatchKeyEvent (handles backkey here)
        <if shouldOverrideKeyevent returns false>
     -> dispatch keyevent to renderer
        <if renderer doesn't consume the keyevent>
        -> web_contents_delegate::HandleKeyboardEvent
           -> XWalkWebContentDelegate.handleKeyboardEvent
              -> XWalkClient.onUnhandledKeyevent

It's pre-adjust for Embedding API v2.

Related to bug: XWALK-2003
[Android] Mark content as a local scheme in blink

Now there is no option to enable the cross-origin-access in the
context of content url in embedded mode. Regarding file scheme we
use setAllowUniversalAccessFromFileURLs option to support the
cross-orign-access. This way works for all the schemes which are
recognized as the "local" ones in blink. That's straightforward
to let content scheme follow this way to support the
cross-orgin-access setting.

BUG=XWALK-1959
Merge pull request #2130 from xingnan/1959

[Android] Mark content as a local scheme in blink
Merge pull request #2129 from wang16/keydispatch_api

[Android] Refine the key event dispatch for xwalkview
Bump version to 8.36.161.0
[Android] Add the core internal shell and the test project.

This patch is to add the core internal shell and test code for internal
shell.
All of the codes are modified from the core shell and core test project.