Add libabsl_flags library to Android.bp

Bug: 121267023
Test: build cxx_extractor and protoc_extractor
Change-Id: Ife96b82d5bbd8b1ae27fd30ef05f29a43c096dad
diff --git a/Android.bp b/Android.bp
index 732a151..ed13415 100644
--- a/Android.bp
+++ b/Android.bp
@@ -45,6 +45,23 @@
 }
 
 cc_library_host_static {
+    name: "libabsl_flags",
+    srcs: [
+        "absl/flags/usage_config.cc",
+        "absl/flags/marshalling.cc",
+        "absl/flags/usage.cc",
+        "absl/flags/flag.cc",
+        "absl/flags/parse.cc",
+        "absl/flags/internal/program_name.cc",
+        "absl/flags/internal/registry.cc",
+        "absl/flags/internal/usage.cc",
+        "absl/flags/internal/type_erased.cc",
+        "absl/flags/internal/commandlineflag.cc",
+        "absl/flags/flag_test_defs.cc",
+    ],
+}
+
+cc_library_host_static {
     name: "libabsl_hash",
     srcs: [
         "absl/hash/internal/city.cc",