Revert "Merge "Revert "Use aidl::nullable for nullable type in C++"" into rvc-dev-plus-aosp am: 9beacac0c9 am: bd9b7af30e am: ec09e10ca3"

This reverts commit b1d388c75118bb5de5bd1727263bf9e752fa936e.

Reason for revert: Unintended revert got merged.

Change-Id: I85637ae4e88a9dcd233b3c17c6030fb726d5681f

Exempt-From-Owner-Approval: reverting unintended revert
3 files changed