IMS-VT: Handle InCallActivity destroy when low battery dialog is showing

Handle InCallActivity destroy by dismissing the existing low battery dialog
and marking the entry against the call in low battery map that the low battery
indication needs to be reprocessed for eg. when user brings back the call to
foreground by pulling it from notification bar.

Change-Id: I0ef5912e39586a601774d7ce450daeadd73d830a
CRs-Fixed: 1064492
2 files changed