Clean up profile AddMethod APIs

Restructure the profile assistant test to use the same APIs as profile
saver and
clean up all the other usages for AddMethodIndex and AddMethod.

Bug: 139884006
Test: m test-art-host

Change-Id: Icf76d6aa05f0f9dcc589182196ca34a0298f2cb7
diff --git a/test/ProfileTestMultiDex/main.list b/test/ProfileTestMultiDex/main.list
index ec131f0..6ca79d4 100644
--- a/test/ProfileTestMultiDex/main.list
+++ b/test/ProfileTestMultiDex/main.list
@@ -5,3 +5,4 @@
 SubB.class
 SubD.class
 SubE.class
+ZLotsOfMethods.class