Bug 997578 - [1.4] Answer incoming call after hanging up active call, a=1.4+
Merge pull request #18698 from nullaus/bug999511

bug 999511(cherry picked from commit 725a23802708eb70e3d7e8a2ce7179adbac806e4)
Merge pull request #18761 from nullaus/v1.4

Merge pull request #18698 from nullaus/bug999511
Merge pull request #18639 from crdlc/bug-1000454

Bug 1000454 - [B2G][1.4][Gaia]: The timestamp for a file downloaded a we...
Merge pull request #18727 from bentian/bug-997578-14

Bug 997578 - [1.4] Answer incoming call after hanging up active call, r=etienne, a=1.4+