Put only src in FRAMEWORKS_SUPPORT_JAVA_SRC_DIRS for multidex

This keeps only the real sources in doc target and fixes some error
messages caused by trying to generate docs of the tests.

(cherry picked from commit 100aba5374376f679602387db59fccd609b8abe3)

Change-Id: I39f3ede95ae68777ca5e3db4ab5c6ebeefc86ac6
diff --git a/core/pathmap.mk b/core/pathmap.mk
index a4a60fa..30b1ab7 100644
--- a/core/pathmap.mk
+++ b/core/pathmap.mk
@@ -118,7 +118,7 @@
         v17/leanback
 
 #
-# A list of all source roots under frameworks/support.
+# A list of all source roots under frameworks/multidex.
 #
 FRAMEWORKS_MULTIDEX_SUBDIRS := \
         multidex \
@@ -130,7 +130,7 @@
 #
 FRAMEWORKS_SUPPORT_JAVA_SRC_DIRS := \
 	$(addprefix frameworks/support/,$(FRAMEWORKS_SUPPORT_SUBDIRS)) \
-        $(addprefix frameworks/,$(FRAMEWORKS_MULTIDEX_SUBDIRS))
+        $(addsuffix /src,$(addprefix frameworks/,$(FRAMEWORKS_MULTIDEX_SUBDIRS)))
 
 #
 # A list of support library modules.