Internal change
Internal change

Release-Id: cloud_spanner_emulator_0.7.8_test_20200423_00_RC01

GoogleCloudPlatform/cloud-spanner-emulator,GoogleCloudPlatform/cloud-spanner-emulator,GoogleCloudPlatform/cloud-spanner-emulator,GoogleCloudPlatform/cloud-spanner-emulator,GoogleCloudPlatform/cloud-spanner-emulator