Export TARGET_JAVAC and HOST_JAVAC to make

Export TARGET_JAVAC and HOST_JAVAC to make.  This moves control
of the javac command line flags into soong.

Test: m -j checkbuild
Merged-In: Ifa3e35be0abd2778741680216427403ba58a0a3b
Change-Id: Ifa3e35be0abd2778741680216427403ba58a0a3b
(cherry picked from commit 2478d8b88527f52c73572e6d868861cd57341271)
diff --git a/java/config/makevars.go b/java/config/makevars.go
index ac02782..29ef57d 100644
--- a/java/config/makevars.go
+++ b/java/config/makevars.go
@@ -37,4 +37,12 @@
 	ctx.Strict("JAR_ARGS", "${JarArgsCmd}")
 	ctx.Strict("JAVADOC", "${JavadocCmd}")
 	ctx.Strict("COMMON_JDK_FLAGS", "${CommonJdkFlags}")
+
+	if ctx.Config().IsEnvTrue("RUN_ERROR_PRONE") {
+		ctx.Strict("TARGET_JAVAC", "${ErrorProneCmd}")
+		ctx.Strict("HOST_JAVAC", "${ErrorProneCmd}")
+	} else {
+		ctx.Strict("TARGET_JAVAC", "${JavacCmd} ${CommonJdkFlags}")
+		ctx.Strict("HOST_JAVAC", "${JavacCmd} ${CommonJdkFlags}")
+	}
 }