Bump required api-core version to 1.17.2

Author: lidizheng

gapic/templates/setup.py.j2

@@ -16,7 +16,7 @@ setuptools.setup(
     platforms='Posix; MacOS X; Windows',
     include_package_data=True,
     install_requires=(
-        'google-api-core[grpc] >= 1.17.0, < 2.0.0dev',
+        'google-api-core[grpc] >= 1.17.2, < 2.0.0dev',
         'libcst >= 0.2.5',
         'proto-plus >= 0.4.0',
     {%- if api.requires_package(('google', 'iam', 'v1')) %}