Revert "Set up Multi-HAL for Sensors HAL 2.1"

Revert submission 10501254-multihal_2_1



Reason for revert: Droidcop: Potential culprit for b/155328660 - verifying through Forrest before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted.

Bug: 155328660
Reverted Changes:
I2be51568b:Update tests for multihal to test HAL 2.1
Id5ab7b606:Create Multi-HAL 2.1 service
Icefae8c12:Set up Multi-HAL for Sensors HAL 2.1

Change-Id: I21176759d45972cde3221cb462934fc1d7bd88c2