USB: [API feedback] Add bitmask @IntDef annonation to setCurrentFunctions

Bug: 148285097
Test: Manual test: USB function switch: MTP, PTP, RNDIS, MIDI
Test: atest UsbTests
Test: atest UsbManagerTests
Change-Id: I27f8097b0a8174f7c1d14b856442e8962b56a906
2 files changed