Auto-detect libsnappy package name
Auto-detect libsnappy package name

On ubuntu-16.04, libsnappy1 is no longer available. Instead, use
libsnappy1v5.

GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,meteorfox/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,meteorfox/PerfKitBenchmarker