gn2bp: Pass additional cflags to reduce cronet library size

Bug: 265913942
Test: ./update_results.sh
Change-Id: Ib802862d1ccab4b8cc2906a0f08aa2d3bddef9e2
diff --git a/tools/gn2bp/gen_android_bp b/tools/gn2bp/gen_android_bp
index 79860fe..94b96e6 100755
--- a/tools/gn2bp/gen_android_bp
+++ b/tools/gn2bp/gen_android_bp
@@ -126,6 +126,20 @@
   "-msse3",
   # needed for zlib:zlib
   "-msse4.2",
+  # flags to reduce binary size
+  "-O1",
+  "-O2",
+  "-O3",
+  "-Oz",
+  "-g1",
+  "-g2",
+  "-fdata-sections",
+  "-ffunction-sections",
+  "-fvisibility=hidden",
+  "-fvisibility-inlines-hidden",
+  "-fstack-protector",
+  "-mno-outline",
+  "-mno-outline-atomics"
 ]
 
 # Linker flags which are passed through to the blueprint.