Add hpd and link training status to displayport alt mode api

Adds isHotPlugDetectActive() and getLinkTraining() status to
DisplayPortAltModeInfo as well as necessary enums within
LINK_TRAINING_STATUS_

Test: atest CtsUsbManagerTestCases
Bug: 253534975
Change-Id: Ibbd3cd979b352f49819a7da01f030abfcae66444
3 files changed