Use soong_droiddoc_prebuilt.mk

Soong droiddoc modules were using soong_java_prebuilt.mk, but they
don't need any of the java logic from it, and it includes
base_rules.mk which was not included by droiddoc.mk.  Use
soong_droiddoc_prebuilt.mk that just installs the droiddoc
outputs without including base_rules.mk.

Fixes building docs modules in mm, mma, and m checkbuild.

Bug: 112388925
Test: m docs
Change-Id: I8ccbcd34adf268a830ee1a203270b955ea696701
diff --git a/java/androidmk.go b/java/androidmk.go
index 14e9fec..04e92c9 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -285,7 +285,7 @@
 	return android.AndroidMkData{
 		Class:      "JAVA_LIBRARIES",
 		OutputFile: android.OptionalPathForPath(jd.stubsSrcJar),
-		Include:    "$(BUILD_SYSTEM)/soong_java_prebuilt.mk",
+		Include:    "$(BUILD_SYSTEM)/soong_droiddoc_prebuilt.mk",
 		Extra: []android.AndroidMkExtraFunc{
 			func(w io.Writer, outputFile android.Path) {
 				if BoolDefault(jd.properties.Installable, true) {
@@ -303,7 +303,7 @@
 	return android.AndroidMkData{
 		Class:      "JAVA_LIBRARIES",
 		OutputFile: android.OptionalPathForPath(ddoc.stubsSrcJar),
-		Include:    "$(BUILD_SYSTEM)/soong_java_prebuilt.mk",
+		Include:    "$(BUILD_SYSTEM)/soong_droiddoc_prebuilt.mk",
 		Extra: []android.AndroidMkExtraFunc{
 			func(w io.Writer, outputFile android.Path) {
 				if BoolDefault(ddoc.Javadoc.properties.Installable, true) {