Blacklist CFI unrelated cast issue in protoc generated code

protoc 3.5.2 generates code that contains an unrelated cast that
causes a CFI error.  Blacklist it for now.

Test: boot with protoc 3.5.2, set screen lock pattern
Bug: 119127110
Change-Id: Ib891628955754f170ce0bb5cf63716961a57b21b
diff --git a/lib/cfi/cfi_blacklist.txt b/lib/cfi/cfi_blacklist.txt
index 1f0eeb3..644b078 100644
--- a/lib/cfi/cfi_blacklist.txt
+++ b/lib/cfi/cfi_blacklist.txt
@@ -24,3 +24,6 @@
 # Windows C++ stdlib headers that contain bad unrelated casts.
 src:*xmemory0
 src:*xstddef
+
+# b/119127110
+fun:*internal_default_instance*