Add foreground flag to AG_CALL_CHANGED broadcast intent.

To fix the issue that the watch is still ringing after answer an
incoming call on phone. It is caused by the ACTION_CALL_CHANGED
broadcast reception processing delayed.

Bug:29931814

Change-Id: I8d8f297c3a13dfe65674eca94724a50d82618f5e
Signed-off-by: m00230717 <m00230717@notesmail.huawei.com>