bump branch android sdk to v2+
bump branch android sdk to v2+

BranchMetrics/react-native-branch,BranchMetrics/react-native-branch-deep-linking,BranchMetrics/react-native-branch-deep-linking,BranchMetrics/react-native-branch,BranchMetrics/react-native-branch,BranchMetrics/react-native-branch-deep-linking,BranchMetrics/react-native-branch,BranchMetrics/react-native-branch,BranchMetrics/react-native-branch-deep-linking,BranchMetrics/react-native-branch