android.hardware.graphics.allocator@2.0 is no longer VNDK-SP

The interface lib has been in VNDK-SP because
android.hardware.graphics.mapper@1.0 was using it. However, since the
dependency has gone [1], there is no need keep it in VNDK-SP. The
VNDK-SP set should be kept as small as possible because libs in VNDK-SP
are subject to double-loading.

[1] https://android.googlesource.com/platform/hardware/interfaces/+/79d13ff0f5cd3c4242445baf5b2f01a52f0ed06f

Bug: 69480083
Test: /system/lib64/vndk-sp/android.hardware.graphics.allocator@2.0.so
disappears.
Test: sailfish boots

Change-Id: I0e6518f169dd620d6b1a9ada47754e371ef4a739
Merged-In: I0e6518f169dd620d6b1a9ada47754e371ef4a739
(cherry picked from commit 9d898f36)