Sync eng/common directory with azure-sdk-tools for PR 1560#821

azure-sdk merged 2 commits intomasterAzure/azure-sdk-for-ios:masterfrom

sync-eng/common-benbp/merge-multiple-sub-configs-1560Azure/azure-sdk-for-ios:sync-eng/common-benbp/merge-multiple-sub-configs-1560Copy head branch name to clipboard