Add TaskType to ScheduleInfo.

Add a task type field to schedule serverless remote task. We want
to introduce an ENTER_GARAGE_MODE type where the external system
can set the AP_POWER_BOOT_UP_REASON and makes android enter
garage mode.

Test: atest RemoteAccessServiceUnitTest
Bug: 316233421
Change-Id: Iddbd2a14aa6f4672a2e27f0a05ec2b73b7d1aab2