Camera: Allow direct selection of operating mode

Instead of a true/false switch for high-speed mode, use an integer
enum instead and define the two existing modes, plus the start
of a vendor mode space.

For all non-high-speed modes, use the normal configuration path,
but pass the operating mode to the HAL.

Test: New CTS test passes
Bug: 34853980
Change-Id: I9dc2b2a2164e9779f079a30e936c4117bcf96efe