Gallery2: Fix filmstrip source index

Filmstrip has 1 item more (the camera itself). Do not count the Camera as an item

Change-Id: I2027d857c08477cb0303e74c15818be1fc979104
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>
(cherry picked from commit 4dd53c7e57878d7cd361f8a45751dd3bb2af1531)
Gallery2: Fix showOnMap method

If the context is ProxyLauncher, showOnMap will make crash the Gallery app if
GoogleMaps not exists, because the double call to startActivity.
Just query the intent before call the startActivity method.

Change-Id: I2e2637626d9f81780f48625bef52e861180e002c
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>
(cherry picked from commit c10a326b5862e3769851fe4349eaa5a18bd17d31)