[Android][Manifest] Remove the unused member of the manifest for packaging tool
[Android][Extension] Use native Promise in Javascript

Some old extensions are still using requireNative('sysapps_promise').
This commit is to replace them with the Javacript build-in Promise.

BUG=https://crosswalk-project.org/jira/browse/XWALK-1678
Merge pull request #2196 from deqing/promise

[Android][Extension] Use native Promise in Javascript
[Android] Fix potential memory leak in XWalkViewInternal

Use WeakReference to register ActivityStateListener.
Otherwise, the ActivityStateListener will hold
a reference of XWalkViewInternal as in static observer
list.
Merge pull request #2192 from jinbang/tool_remove_unused_manifest_field

[Android][Manifest] Remove the unused member of the manifest for packagi...
Bump version to 8.36.173.0
Merge pull request #2198 from wang16/fix_activity_listener_leak

[Android] Fix potential memory leak in XWalkViewInternal
[Android] Rename version to xwalk_version in manifest and make it optional

According W3C manifest spec, 'version' field of manifest should be:
1) renamed to "xwalk_version"
2) optional
3) the "version" field should be handled if present, but issue a deprecation warning

BUG=https://crosswalk-project.org/jira/browse/XWALK-2053