Remove implementation details from i18n hidden api flags am: d66e1e13fb am: 8b5d456f1a am: bc61ffe7ca am: a529a236d0

Original change: https://android-review.googlesource.com/c/platform/packages/modules/RuntimeI18n/+/2026764

Change-Id: Ibff6eea7317218eb21b0c09d51b71790e308f6ea