Remove obsolete proguard options

LOCAL_PROGUARD_ENABLED := shrinktests is never set.
proguard_tests.flags is entirely comments.
proguard.emma.flags only references emma classes, but we use
jacoco now.

Test: m checkbuild
Change-Id: I84a59a8c1b66f75d7ccbaa7da8e937430b4490c8
diff --git a/core/java.mk b/core/java.mk
index cfe2539..6e9fea0 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -593,7 +593,7 @@
 
 # Run proguard if necessary
 ifdef LOCAL_PROGUARD_ENABLED
-ifneq ($(filter-out full custom nosystem obfuscation optimization shrinktests,$(LOCAL_PROGUARD_ENABLED)),)
+ifneq ($(filter-out full custom nosystem obfuscation optimization,$(LOCAL_PROGUARD_ENABLED)),)
     $(warning while processing: $(LOCAL_MODULE))
     $(error invalid value for LOCAL_PROGUARD_ENABLED: $(LOCAL_PROGUARD_ENABLED))
 endif
@@ -634,15 +634,8 @@
 common_proguard_flag_files :=
 ifeq ($(filter nosystem,$(LOCAL_PROGUARD_ENABLED)),)
 common_proguard_flag_files += $(BUILD_SYSTEM)/proguard.flags
-ifeq ($(LOCAL_EMMA_INSTRUMENT),true)
-common_proguard_flags += -include $(BUILD_SYSTEM)/proguard.emma.flags
-endif
-# If this is a test package, add proguard keep flags for tests.
 ifneq ($(LOCAL_INSTRUMENTATION_FOR)$(filter tests,$(LOCAL_MODULE_TAGS)),)
-common_proguard_flag_files += $(BUILD_SYSTEM)/proguard_tests.flags
-ifeq ($(filter shrinktests,$(LOCAL_PROGUARD_ENABLED)),)
 common_proguard_flags += -dontshrink # don't shrink tests by default
-endif # shrinktests
 endif # test package
 ifneq ($(LOCAL_PROGUARD_ENABLED),custom)
   ifdef LOCAL_USE_AAPT2