Proguard implicitly generates a proguard_dictionary

Use .KATI_IMPLICIT_OUTPUTS to convey as such.

This is to support a use case for building platform/art/tools/ahat,
which depends on the generated proguard_dictionary for running tests.

Test: m
Test: m ahat-test with relevant changes from clean build.
Change-Id: Ic8f3b6819cfd4cd18620a2eaafd80d672fde8f5c
diff --git a/core/java.mk b/core/java.mk
index 4a6535c..d914c52 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -707,6 +707,7 @@
 endif
 endif
 
+$(full_classes_proguard_jar): .KATI_IMPLICIT_OUTPUTS := $(proguard_dictionary)
 $(full_classes_proguard_jar): PRIVATE_PROGUARD_INJAR_FILTERS := $(proguard_injar_filters)
 $(full_classes_proguard_jar): PRIVATE_EXTRA_INPUT_JAR := $(extra_input_jar)
 $(full_classes_proguard_jar): PRIVATE_PROGUARD_FLAGS := $(legacy_proguard_flags) $(common_proguard_flags) $(LOCAL_PROGUARD_FLAGS)