Fixes an issue where the HWC init randomly blocks on the
allocator init by doing a lazy initialization of the allocator
object. The allocator may not have fully initialized at HWC init.
Also, increases the allocator connection threadpool to 4.
Change-Id: I38454ee25aaf2a211125e55297300eac754fb5cf
CRs-Fixed: 2201202
Implement the hidl .hal interfaces directly instead of using the
default shims.
This is required since new additions to .hal will no longer be
added to the legacy gralloc1 C header.
Change-Id: If577a14f75d7d13da0ff656c96ab451d21c910ce
