[Android] Fix XWalkCoreInternalTest failure

Including:
ExtensionBroadcastInternalTest#test
ExtensionEchoInternalTest#testMultiFrames
WebNotificationTest#testWebNotificationShowAndCloseByUser
WebNotificationTest#testWebNotificationShowAndCloseByJs

BUG=https://crosswalk-project.org/jira/browse/XWALK-3215