Add DVR method to get native display metrics

This seems like the kind of infomration we should be able to communicate
to vrcore.

Bug: 62494565
Test: Builds and loads, still need to test with vrcore
Change-Id: I2342fabcd2bcb8a34c0b783391b60defc381f3c6
(cherry picked from commit 6c5a92f142b5fa1907ff91a7dce4d09ddcb554c6)
4 files changed