Fix handling of "prebuilt_" prefix in classLoaderContextForUsesLibDeps.

Changes:
- Cut off "prebuilt_" prefix from `dep`, not `libName`, because `dep` is
  used to replace library name in `usesLibraryProperties`, and these
  properties are specified without "prebuilt_" prefix.

- Do not remove "prebuilt_" prefix on the return value of
  `ProvidesUsesLib()`: this boils down to `provides_uses_lib` property
  which is specified without the prefix.

Bug: 193425964
Test: $ lunch aosp_cf_x86_64_phone-userdebug && m && launch_cvd
      $ adb wait-for-device && \
        adb root && \
        adb logcat | \
        grep -E 'ClassLoaderContext [a-z ]+ mismatch' -C1
      # empty output, no errors
Change-Id: I6cb65040027023d12ca0bc132d60c2c245174c40
diff --git a/java/app.go b/java/app.go
index d464e38..4456b22 100755
--- a/java/app.go
+++ b/java/app.go
@@ -1262,12 +1262,12 @@
 			return
 		}
 
-		dep := ctx.OtherModuleName(m)
+		dep := android.RemoveOptionalPrebuiltPrefix(ctx.OtherModuleName(m))
 
 		if lib, ok := m.(UsesLibraryDependency); ok {
-			libName := android.RemoveOptionalPrebuiltPrefix(dep)
+			libName := dep
 			if ulib, ok := m.(ProvidesUsesLib); ok && ulib.ProvidesUsesLib() != nil {
-				libName = android.RemoveOptionalPrebuiltPrefix(*ulib.ProvidesUsesLib())
+				libName = *ulib.ProvidesUsesLib()
 				// Replace module name with library name in `uses_libs`/`optional_uses_libs` in
 				// order to pass verify_uses_libraries check (which compares these properties
 				// against library names written in the manifest).