ANDROID: Fix the drain_all_pages default condition broken by a hook

The condition introduced by a patch adding a vendor hook to skip
drain_all_pages is invalid and changes the default behavior for CMA
allocations. Fix the condition to restore default behavior.

Fixes: a2485b8a ("ANDROID: vendor_hooks: Add hooks to for alloc_contig_range")
Bug: 232357688
Reported-by: Yong-Taek Lee <ytk.lee@samsung.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: I686ad9dff57f604557f79cf4dc12cde55474e533