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/java/classpath_fragment.go b/java/classpath_fragment.go
index 12bb711..f63d81d 100644
--- a/java/classpath_fragment.go
+++ b/java/classpath_fragment.go
@@ -91,8 +91,8 @@
 	maxSdkVersion int32
 }
 
-// gatherPossibleUpdatableModuleNamesAndStems returns a set of module and stem names from the
-// supplied contents that may be in the updatable boot jars.
+// gatherPossibleApexModuleNamesAndStems returns a set of module and stem names from the
+// supplied contents that may be in the apex boot jars.
 //
 // The module names are included because sometimes the stem is set to just change the name of
 // the installed file and it expects the configuration to still use the actual module name.
@@ -100,7 +100,7 @@
 // The stem names are included because sometimes the stem is set to change the effective name of the
 // module that is used in the configuration as well,e .g. when a test library is overriding an
 // actual boot jar
-func gatherPossibleUpdatableModuleNamesAndStems(ctx android.ModuleContext, contents []string, tag blueprint.DependencyTag) []string {
+func gatherPossibleApexModuleNamesAndStems(ctx android.ModuleContext, contents []string, tag blueprint.DependencyTag) []string {
 	set := map[string]struct{}{}
 	for _, name := range contents {
 		dep := ctx.GetDirectDepWithTag(name, tag)