graphics: clarify importBuffer and passthrough HALs

A buffer handle recieved from a HAL is by definition raw and needs
to be imported.  But because of passthrough HALs, such a raw handle
may have been imported already.  Explicitly specify that an
implementation must accept such a raw handle.

Bug: 37540361
Test: boots on angler, ryu and marlin
Change-Id: I5ecf526e59b27cc4a8f7f5d5ec27477da0946ece
diff --git a/current.txt b/current.txt
index 575e8fa..2b46fcb 100644
--- a/current.txt
+++ b/current.txt
@@ -103,7 +103,7 @@
 b19d00eb8a8b3b0034a0321f22e8f32162bf4c2aebbce6da22c025f56e459ea2 android.hardware.graphics.composer@2.1::IComposerCallback
 e992684e690dfe67a8cbeab5005bfa3fa9c2bf3d4b0b75657fb1f0c2d5dd2bae android.hardware.graphics.composer@2.1::IComposerClient
 1c98c2f5154345312ec054871792a2982ec5f3e2bc2abfb61a10c0b517978e20 android.hardware.graphics.composer@2.1::types
-04fbe91f2a860d463fa6287fbcfa05a8cc4f17848cabcd2aa9eef0f2aa1fedc0 android.hardware.graphics.mapper@2.0::IMapper
+a695898589e1ef15b2b2510f11edd6aafac9918d9cf8d74b4b6143b309dee542 android.hardware.graphics.mapper@2.0::IMapper
 28507d385a3dd224bf3c32f1bfd9f96092c4701b9c1cc66caa578fc3efc97877 android.hardware.graphics.mapper@2.0::types
 91e2ba3805c923f01fc1231ec9ff838942aee3346f2d7614ecc0caeadbe57ed4 android.hardware.health@1.0::IHealth
 1275aa2e8732909101b26aec49ed2285489e89d97b8610a8908b7868e35a3cc5 android.hardware.health@1.0::types