Replace DEX_FLAGS by flags for D8 and R8.

This adds the heap space flag currently set in wrappers.

Bug: b/227746536
Test: manual
Change-Id: Ic3cb8feb7a09d690ecd309162236e49a8d1e52c6
diff --git a/java/config/makevars.go b/java/config/makevars.go
index bc6848f..273aca0 100644
--- a/java/config/makevars.go
+++ b/java/config/makevars.go
@@ -43,9 +43,10 @@
 	ctx.Strict("JAVADOC", "${JavadocCmd}")
 	ctx.Strict("COMMON_JDK_FLAGS", "${CommonJdkFlags}")
 
-	ctx.Strict("DX", "${D8Cmd}")
-	ctx.Strict("DX_COMMAND", "${D8Cmd} -JXms16M -JXmx2048M")
-	ctx.Strict("R8_COMPAT_PROGUARD", "${R8Cmd}")
+	ctx.Strict("D8", "${D8Cmd}")
+	ctx.Strict("R8", "${R8Cmd}")
+	ctx.Strict("D8_COMMAND", "${D8Cmd} ${D8Flags}")
+	ctx.Strict("R8_COMMAND", "${R8Cmd} ${R8Flags}")
 
 	ctx.Strict("TURBINE", "${TurbineJar}")
 
@@ -78,9 +79,6 @@
 	ctx.Strict("CLASS2NONSDKLIST", "${Class2NonSdkList}")
 	ctx.Strict("HIDDENAPI", "${HiddenAPI}")
 
-	ctx.Strict("D8_FLAGS", "${D8Flags}")
-	ctx.Strict("R8_FLAGS", "${R8Flags}")
-
 	ctx.Strict("AIDL", "${AidlCmd}")
 	ctx.Strict("AAPT2", "${Aapt2Cmd}")
 	ctx.Strict("ZIPALIGN", "${ZipAlign}")