Fix NPE when controller has no set package name

This can happen with the media session binder connection is broken
before getPackageName has been called.

Bug: 290809698
Test: mp droid
Test: atest CtsMediaMiscTestCases
(cherry picked from https://android-review.googlesource.com/q/commit:6a62fe4e22762390eadf68c5bfab8cf27c37839d)
Merged-In: Ia7f4bb6c7d531c5c30850aede9f8b95dd6d2cdcc
Change-Id: Ia7f4bb6c7d531c5c30850aede9f8b95dd6d2cdcc