Android: Avoid unnecessary methodId lookups (use a cache instead)

This is a performance improvement.

Change-Id: If3115078ae3247f9f888982b922a77c9cd92fe91
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Android: Fix crash while retrieving GPS based location.

The satellite backend was not properly guarded from the location backend.
As a consequence satellite updates were triggered while
the user only requested position updates. This caused uninitialized
satellite code to be exeuted which caused an abort.

Change-Id: I4a7511d49ba795fb6a4fc8e9c723ef1260c5c9a5
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Don't use QString if not required (Performance improvement)

Change-Id: I80cf4dcd98c45169b31ee1659122020ce27b29ea
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>