Removing startActivityForResult from BaseActivity

Fixing the back button delay by removing the startActivityForResult
call. This was causing issues as activities that finished were waiting
for a result still and holding up the flow.

Fixes: 120303848
Test: No more back button delay in flow

Change-Id: I521c17a1a056b00b995d96a9a4f5a5e6fa3db254
(cherry picked from commit d1fad7364842abcafd6f473d08edd3bac62aa7c6)