Expose input association to be testable

- Expose api via TestApi
- Add ASSOCIATE_INPUT_DEVICE_TO_DISPLAY permission to Shell
- Add port for uinput command

Bug: 215631144
Test: atest CtsInputTestCases
Ignore-AOSP-First: Permission that should be kept internal until T releases
Change-Id: I55f2141aabceb71475f5e7f7d590b2f95e05c5aa