Add apache-xml to core-system-modules

Add apache-xml to core-system-modules for completeness/
correctness.

Bug: 113148576
Test: build
Change-Id: I5fdb422556fa9c5c7f3185627a08639371e9397d
diff --git a/JavaLibrary.bp b/JavaLibrary.bp
index 14dada6..bbe1539 100644
--- a/JavaLibrary.bp
+++ b/JavaLibrary.bp
@@ -343,6 +343,7 @@
         "bouncycastle",
         "conscrypt",
         "okhttp",
+        "apache-xml",
         // This one is not on device but it's needed when javac compiles code
         // containing lambdas.
         "core-lambda-stubs",