Pass application packagename to drm plugin.

Pass application package name to createPlugin and createDrmPlugin.
The application packagename will be used as part of a unique
identifier for drm plugin.

Test: Play Movies.

Test: ANDROID_BUILD_TOP= ./android-gts/tools/gts-tradefed run gts -m
GtsMediaTestCases --test
com.google.android.media.gts.WidevineH264PlaybackTests#testL1With480P60

Verify the application's packagename is reachable in the drm plugin's
debug log.

bug: 27101531

Change-Id: I84fb09b591a7af63f6e20004e910112a4ce6ebac