jpegrecoverymap: Update XMP to match spec.

Remove TransferFunction and PQ metadata from XMP, since they are no
longer needed. Update RangeScalingFactor to MaxContentBoost. Also update
GContainer prefix to Container and correct Item to be its own prefix, in
order to properly conform to GContainer.

In order to still provide a decode flow, default to HLG.

Bug: 264715926
Test: tests pass
Change-Id: I6a94a74666381637c4a7ad301de05cf562c53265
diff --git a/libs/jpegrecoverymap/tests/recoverymap_test.cpp b/libs/jpegrecoverymap/tests/recoverymap_test.cpp
index dfab76a..3e9a76d 100644
--- a/libs/jpegrecoverymap/tests/recoverymap_test.cpp
+++ b/libs/jpegrecoverymap/tests/recoverymap_test.cpp
@@ -103,8 +103,7 @@
 
 TEST_F(RecoveryMapTest, writeXmpThenRead) {
   jpegr_metadata metadata_expected;
-  metadata_expected.transferFunction = JPEGR_TF_HLG;
-  metadata_expected.rangeScalingFactor = 1.25;
+  metadata_expected.maxContentBoost = 1.25;
   int length_expected = 1000;
   const std::string nameSpace = "http://ns.adobe.com/xap/1.0/\0";
   const int nameSpaceLength = nameSpace.size() + 1;  // need to count the null terminator
@@ -120,8 +119,7 @@
 
   jpegr_metadata metadata_read;
   EXPECT_TRUE(getMetadataFromXMP(xmpData.data(), xmpData.size(), &metadata_read));
-  ASSERT_EQ(metadata_expected.transferFunction, metadata_read.transferFunction);
-  ASSERT_EQ(metadata_expected.rangeScalingFactor, metadata_read.rangeScalingFactor);
+  ASSERT_EQ(metadata_expected.maxContentBoost, metadata_read.maxContentBoost);
 }
 
 /* Test Encode API-0 and decode */