Switch to gnu++11 for libFuzzer.

This library is an older snapshot that only works with C++11.

Bug: http://b/111067277
Test: Build with default cpp_std as C++17.
Change-Id: I3e49d5843bcde0a30f06802d21aa12a6a2140291
diff --git a/lib/Fuzzer/Android.bp b/lib/Fuzzer/Android.bp
index d8de2eb..2bd550f 100644
--- a/lib/Fuzzer/Android.bp
+++ b/lib/Fuzzer/Android.bp
@@ -25,6 +25,7 @@
         "-Wno-unused-lambda-capture",
         "-Wno-unused-parameter",
     ],
+    cpp_std: "gnu++11",
     srcs: ["*.cpp"],
     exclude_srcs: ["FuzzerMain.cpp"],
     sanitize: {
@@ -43,6 +44,7 @@
         "-Wno-unused-lambda-capture",
         "-Wno-unused-parameter",
     ],
+    cpp_std: "gnu++11",
     srcs: ["FuzzerMain.cpp"],
     whole_static_libs: ["libLLVMFuzzerNoMain"],
     sanitize: {