versioner: start using C++17.

Bug: None
Test: python run_tests.py
Change-Id: I10101d26b7816a83445f25b33b97ed47d42fd135
diff --git a/tools/versioner/src/Android.bp b/tools/versioner/src/Android.bp
index 6e1d750..d1362d0 100644
--- a/tools/versioner/src/Android.bp
+++ b/tools/versioner/src/Android.bp
@@ -37,6 +37,7 @@
     target: {
         host: {
             cppflags: [
+                "-std=gnu++1z",
                 "-fno-rtti",
             ],
         },