Introduces the Bundle to inline suggestions APIs to encode custom UI styling information.

* The bundle will be generated/consumed by the support library.
* More API documentation and example usage will be added later once we have the support library impl ready.
* The old style resource name approach doesn't work due to the potential mismatch in the support library version across the host IME and the platform renderer service, and the non-static nature of the public attribute int id in the support lib.
* The Bundle added to the onCreateInlineSuggestionsRequest() is intended for the platform/ExtServices to communicate the UI versions it supports.
* The Bundle added to the InlinePresentationSpec is intended for the IME to communicate the custom styles for the chosen UI versions.

Test: manual verification, and also atest CtsInputMethodTestCases:InlineSuggestionInfoTest CtsInputMethodTestCases:InlineSuggestionTest CtsInputMethodTestCases:InlineSuggestionsRequestTest CtsInputMethodTestCases:InlineSuggestionsResponseTest
Bug: 146454892

Change-Id: Id7fea32a7550fb924fec811b376790474a7b92eb