Android: Improve patch_android_prl_files() a bit

Let use a regular expression to match the full path to libgcc.a
instead of using the full path on Linux, Windows and Mac.

Change-Id: I8616af138fd537f2af1efb1eb5451ff10b5e8d0a
Reviewed-by: Iikka Eklund <iikka.eklund@digia.com>