Rename remote hotword detection service usages

All hotword detection service usage are renamed based on their semantic
meaning. Variable names with framework reference have their
HotwordDetection removed, and names refering to the actual
HotwordDetectionService are added.

Bug: 261783492
Test: atest CtsVoiceInteractionTestCases
Change-Id: Ifa9bec8be2f0892a219250b7d68a4fad88de251d