Wait for the capabilities callback before deciding FLP HAL version.

-Some implementations require a modem handshake to determine
 FLP HAL version and can't do it upon initialization.  Wait
 for a v2 callback before assuming that the HAL implementation
 is actually v2.

Bug: 21958418
Change-Id: I7512d293f99363c63580c69d84f80da96a88dd2f