BasicMediaDecoder: Use new build system

Migrate BasicMediaDecoder to use new templatized build system for
conformity with other samples.

Also moved common/src/com/example/android/common/media to
common/src/java/com/example/android/common/media, in order to make it
visible to the template system.

Change-Id: I11613d27bb61f45b92893cfd08b70f788fdc1fc1
32 files changed