Fix remote execution of r8 and d8 in make

1. The location of the r8.jar and d8.jar files was no longer correct.
2. $(JAVA) was not defined before rbe.mk was included.
3. $(JAVA) includes options, which much be stripped to be a rewrapper toolchain input.

Test: ran against an RBE cluster with RBE_D8_EXEC_STRATEGY=remote and RBE_R8_EXEC_STRATEGY=remote

Change-Id: Icf434f5c0fda687c70c75b01b0bfd63bcd8cc474
diff --git a/core/config.mk b/core/config.mk
index f5bb7ef..025a3a1 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -431,6 +431,9 @@
 $(hide) $(HOST_NM) -gP $(1) | cut -f1-2 -d" " | (grep -v U$$ >> $(2) || true)
 endef
 
+# Pick a Java compiler.
+include $(BUILD_SYSTEM)/combo/javac.mk
+
 ifeq ($(CALLED_FROM_SETUP),true)
 include $(BUILD_SYSTEM)/ccache.mk
 include $(BUILD_SYSTEM)/goma.mk
@@ -453,9 +456,6 @@
   WITH_TIDY_ONLY :=
 endif
 
-# Pick a Java compiler.
-include $(BUILD_SYSTEM)/combo/javac.mk
-
 # ---------------------------------------------------------------
 # Check that the configuration is current.  We check that
 # BUILD_ENV_SEQUENCE_NUMBER is current against this value.
diff --git a/core/rbe.mk b/core/rbe.mk
index 65abde5..6754b0a 100644
--- a/core/rbe.mk
+++ b/core/rbe.mk
@@ -81,11 +81,11 @@
   endif
 
   ifdef RBE_R8
-    R8_WRAPPER := $(strip $(RBE_WRAPPER) --labels=type=compile,compiler=r8 --exec_strategy=$(r8_exec_strategy) --platform=$(java_r8_d8_platform) --inputs=$(OUT_DIR)/soong/host/linux-x86/framework/r8-compat-proguard.jar,build/make/core/proguard_basic_keeps.flags --toolchain_inputs=$(JAVA))
+    R8_WRAPPER := $(strip $(RBE_WRAPPER) --labels=type=compile,compiler=r8 --exec_strategy=$(r8_exec_strategy) --platform=$(java_r8_d8_platform) --inputs=$(OUT_DIR)/host/linux-x86/framework/r8.jar,build/make/core/proguard_basic_keeps.flags --toolchain_inputs=$(firstword $(JAVA)))
   endif
 
   ifdef RBE_D8
-    D8_WRAPPER := $(strip $(RBE_WRAPPER) --labels=type=compile,compiler=d8 --exec_strategy=$(d8_exec_strategy) --platform=$(java_r8_d8_platform) --inputs=$(OUT_DIR)/soong/host/linux-x86/framework/d8.jar --toolchain_inputs=$(JAVA))
+    D8_WRAPPER := $(strip $(RBE_WRAPPER) --labels=type=compile,compiler=d8 --exec_strategy=$(d8_exec_strategy) --platform=$(java_r8_d8_platform) --inputs=$(OUT_DIR)/host/linux-x86/framework/d8.jar --toolchain_inputs=$(firstword $(JAVA)))
   endif
 
   rbe_dir :=