Add PackageInstaller#uninstallExistingPackage API to TvSystem am: 74cb65d47b

Change-Id: I99609aa1b6fe062ad70f5260adbf2bbc41890640
tree: c45e98e7f8b8888658a589b1ac4e808862e2cf8a
  1. api/
  2. java/
  3. Android.bp