Remove unused .fs file suppport

.fs files are obsolete.

Bug: 73885582
Test: m checkbuild
Change-Id: I74b618099333fe565c7b235994be64e6466d2da6
Merged-In: I74b618099333fe565c7b235994be64e6466d2da6
(cherry picked from commit 93d6550c5338a68dd6e3bb9cced58902faa9665d)
diff --git a/core/java_common.mk b/core/java_common.mk
index e607bb7..3fdf6ff 100644
--- a/core/java_common.mk
+++ b/core/java_common.mk
@@ -177,7 +177,7 @@
 #####################################
 ## Warn if there is unrecognized file in LOCAL_SRC_FILES.
 my_unknown_src_files := $(filter-out \
-  %.java %.aidl %.proto %.logtags %.fs %.rs, \
+  %.java %.aidl %.proto %.logtags %.rs, \
   $(LOCAL_SRC_FILES) $(LOCAL_INTERMEDIATE_SOURCES) $(LOCAL_GENERATED_SOURCES))
 ifneq ($(my_unknown_src_files),)
 $(warning $(LOCAL_MODULE_MAKEFILE): $(LOCAL_MODULE): Unused source files: $(my_unknown_src_files))