chrome.bluetooth: enable [start|stop]Discovery and register events once only
Reset chrome-apps-api-tests webview to crosswalk by default
moving cca-manifest-logic from node_modules to root
Merge pull request #421 from oahziur/ble-ios-improvement

chrome.bluetooth and chrome.bluetoothLowEnergy changes
CB-7980 Set BUILD_MULTIPLE_APKS only if webview != system

When using system webview, there is no need to build multiple APKs.

See https://issues.apache.org/jira/browse/CB-7980
CB-7980 Set min/target SDK version via manifest

minSdkVersion was previously set in post-prepare.
Now it's copied from manifest to config.xml in pre-prepare.
cordova-lib then copies it from config.xml to AndroidManifest.xml