Rename UpdatableBootJars to ApexBootJars.

Note that ART apex boot jars and core-icu4j are exceptions here as they
are not part of ApexBootJars. ART apex boot jars are defined in their
own variable, while core-icu4j is treated as a regular non-updatable
boot jar.

Bug: 191127295
Test: atest CtsClasspathsTestCases
Change-Id: I3cea3d82ef521655a1a5ffa8cae2258ab9d08bfc
diff --git a/sdk/bootclasspath_fragment_sdk_test.go b/sdk/bootclasspath_fragment_sdk_test.go
index efd2b5b..c7ad798 100644
--- a/sdk/bootclasspath_fragment_sdk_test.go
+++ b/sdk/bootclasspath_fragment_sdk_test.go
@@ -224,7 +224,7 @@
 		java.PrepareForTestWithJavaDefaultModules,
 		java.PrepareForTestWithJavaSdkLibraryFiles,
 		java.FixtureWithLastReleaseApis("mysdklibrary", "myothersdklibrary", "mycoreplatform"),
-		java.FixtureConfigureUpdatableBootJars("myapex:mybootlib", "myapex:myothersdklibrary"),
+		java.FixtureConfigureApexBootJars("myapex:mybootlib", "myapex:myothersdklibrary"),
 		prepareForSdkTestWithApex,
 
 		// Add a platform_bootclasspath that depends on the fragment.
@@ -728,7 +728,7 @@
 		java.PrepareForTestWithJavaDefaultModules,
 		java.PrepareForTestWithJavaSdkLibraryFiles,
 		java.FixtureWithLastReleaseApis("mysdklibrary"),
-		java.FixtureConfigureUpdatableBootJars("myapex:mybootlib"),
+		java.FixtureConfigureApexBootJars("myapex:mybootlib"),
 		prepareForSdkTestWithApex,
 
 		// Add a platform_bootclasspath that depends on the fragment.