Build rules to derive greylists from annotations.

Uses the new class2greylist tool to extract API descriptors from .class
files.

Also add these generated greylist.txt files as dependencies of
INTERNAL_PLATFORM_HIDDENAPI_LIGHT_GREYLIST so they can be merged later in
the build.

Bug: 110868826
Test: m
Change-Id: I406587732b537f9b56768ad9909039dfab34c334
diff --git a/core/config.mk b/core/config.mk
index f7a8176..a6aec9b 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -719,6 +719,7 @@
 DEXDUMP := $(HOST_OUT_EXECUTABLES)/dexdump2$(BUILD_EXECUTABLE_SUFFIX)
 PROFMAN := $(HOST_OUT_EXECUTABLES)/profman
 HIDDENAPI := $(HOST_OUT_EXECUTABLES)/hiddenapi
+CLASS2GREYLIST := $(HOST_OUT_EXECUTABLES)/class2greylist
 
 FINDBUGS_DIR := external/owasp/sanitizer/tools/findbugs/bin
 FINDBUGS := $(FINDBUGS_DIR)/findbugs