Camera2: Add BURST_CAPTURE capability flag

This capability (a subset of FULL) indicates that a camera device
can capture high-rate (>= 20fps) bursts of images at full device
resolution, in at least the YUV_420_888 format.

It also guarantees that the synchronization latency for a device is
relatively small, so that fixed-setting bursts can be captured quickly.

Bug: 18281970
Change-Id: Ifc8fc43252a77097d804429d1c9f6fa71a95aa4f