Merge "Use std::unordered_map in KeyCharacterMap" into udc-dev am: 73fb43b650 am: 8175b4f9e9

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/native/+/22679936

Change-Id: Ie2024a3866802e85d6018b1a82decc245ed4e7a1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>