Check if dialpad is already open when handleing new intents.

If the user had the dialpad open when they received a call, they could
potentially crash dialer if they pressed add call or clicked on a phone number
in another app.

Bug: 74711879
Test: manual
PiperOrigin-RevId: 189371425
Change-Id: I14df55e2467be07dd30e3971004e601216f57daf
1 file changed