[automerger skipped] Add dtmSupported into 1.6 HAL for 2G network am: fb3fa529b2 am: c1f27e9269 am: ef9b932504 -s ours

am skip reason: Change-Id Iba230acda8302df90e77d93701d9b0ba74196fc0 with SHA-1 eb3939467a is in history

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/1574925

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I777f14c833a21d79927957111d05fb11b3d11380