Note that getPackageName() also throws NameNotFoundException, so in the
unlikely situations in case:

- package info (class containing the package version) is not found or
- the package version is not in an "a/b" form

We still just don't show anything.

Also, mark the new TextView as android:textIsSelectable, so it's
possible to copy&paste the version for bugreport purposes.

Change-Id: I63b53cca4126da17bfbda0293d7c98e8524ef41a