Make RemoteTimeText and RemoteTimeTextDefaults public

This change exposes RemoteTimeText and RemoteTimeTextDefaults as public APIs in compose remote material3.

Test: ./gradlew :wear:compose:remote:remote-material3:test
Relnote: "Made `RemoteTimeText` and `RemoteTimeTextDefaults` public APIs in wear:compose:remote:remote-material3."
Change-Id: I83809b58d80692d89b09a94ed4350dfb01ee060d
Bug: 545459916