Current view findFocus maybe null, which cause NullPointerException.
When run monkey test on TabHost application, easily reproduce the NullPointerException.
Refactor bad code to better.
Signed-off-by: duzhaoxi <du.zhaoxi@zte.com.cn>

Change-Id: I80757489e23cedecb18a9bb978c567d02111b53c
Merge "Current view findFocus maybe null, which cause NullPointerException. When run monkey test on TabHost application, easily reproduce the NullPointerException. Refactor bad code to better. Signed-off-by: duzhaoxi <du.zhaoxi@zte.com.cn>" into du44