Support gainmap HW copy.

- for Bitmap::allocateHardwareBitmap to create and upload a hardware
  version of the gainmap.

Bug: 267216439
Test: android.graphics.cts.BitmapFactoryTest,
android.graphics.cts.BitmapRegionDecoderTest,
android.graphics.cts.ImageDecoderTest, android.graphics.cts.GainmapTest

Change-Id: Ie080896425dc82a605b2bc41e97ddc2420f5328a
diff --git a/libs/hwui/jni/ImageDecoder.cpp b/libs/hwui/jni/ImageDecoder.cpp
index fda7080..ad80460 100644
--- a/libs/hwui/jni/ImageDecoder.cpp
+++ b/libs/hwui/jni/ImageDecoder.cpp
@@ -469,8 +469,10 @@
             if (hwBitmap) {
                 hwBitmap->setImmutable();
                 if (nativeBitmap->hasGainmap()) {
-                    // TODO: Also convert to a HW gainmap image
-                    hwBitmap->setGainmap(nativeBitmap->gainmap());
+                    auto gm = uirenderer::Gainmap::allocateHardwareGainmap(nativeBitmap->gainmap());
+                    if (gm) {
+                        hwBitmap->setGainmap(std::move(gm));
+                    }
                 }
                 return bitmap::createBitmap(env, hwBitmap.release(), bitmapCreateFlags,
                                             ninePatchChunk, ninePatchInsets);