Revert "Use rcGetHostExtensions() in HostConnection"

Revert "Add rcGetHostExtensions()"

Revert submission 2216672-gfxstream-rcgethostextensionsstring

Reason for revert: breaks emulator appcompat b/246959520
Reverted Changes:
I4a40ca645:Use rcGetHostExtensions() in HostConnection
I864c29707:Add rcGetHostExtensions()

Change-Id: Ib34af7af69451dbd65c9d403014e9657c3ff1403
2 files changed