cameraservice: Use ro.board.api_level instead of ro.vndk.version

With trunk stable, ro.vndk.version has been deprecated and replaced
by ro.board.api_level to represent the API version that the vendor
parition is built against.

From Android V onwards, instead of using the SDK version,
ro.board.api_level will store the API level in YYYYMM format.
So Android V will be designated 202404.

This CL updates the logic in CameraService to map the new
YYYYMM values back to SDK API level that is used to filter
CameraMetadata keys.

Bug: 312315580
Test: Manually verified that the mapping is correct.
Change-Id: I569760223e7f1fac4e747339f129bd86c3aa6af1