SurfaceFlinger: add allowed display configs to dumpsys

Dump the allowed display configs from SurfaceFlinger to help with
debugging issues where the refresh rate does not match the policy.

Test: adb shell dumpsys SurfaceFlinger
Bug: 136503733
Change-Id: I74ec7d08901ad9edb1a3706249e8809574bf1e5f
1 file changed