Add codepoint exclusions API

To be used by unbundled glyph drawing code to filter codepoint sequences
excluded on this platform.

Bug: b/242678495
Test: CodepointExclusionsTest
Merged-In: If928e35a162f5c9bda506a641ce6595855e3e399

(cherry-pick)


Change-Id: I5d43adddba59619b479fe096a656c796380fc97d