Remove workaround to remove FlaggedAPI in ump

Tethering/common/TetheringLib/Android.bp

Tethering/common/TetheringLib/udc-extended-api/current.txt

...mmon/TetheringLib/udc-extended-api/module-lib-current.txt

...mmon/TetheringLib/udc-extended-api/module-lib-removed.txt

Tethering/common/TetheringLib/udc-extended-api/removed.txt

...g/common/TetheringLib/udc-extended-api/system-current.txt

...g/common/TetheringLib/udc-extended-api/system-removed.txt

framework-t/Android.bp

framework-t/udc-extended-api/OWNERS

framework-t/udc-extended-api/current.txt

framework-t/udc-extended-api/lint-baseline.txt

framework-t/udc-extended-api/module-lib-current.txt

framework-t/udc-extended-api/module-lib-lint-baseline.txt

framework-t/udc-extended-api/module-lib-removed.txt

framework-t/udc-extended-api/removed.txt

framework-t/udc-extended-api/system-current.txt

framework-t/udc-extended-api/system-lint-baseline.txt

framework-t/udc-extended-api/system-removed.txt

framework/Android.bp

framework/udc-extended-api/current.txt