add metric for rocksdb getLastEntryInLedger to help find out bottleneck #2453

Job	Run time
Typo Check	9s
PR Validation	8m 2s
Backward compatibility tests	31m 38s
Build with macos on JDK 11	2m 9s
Bookie Tests	17m 36s
Integration Tests	18m 45s
Build with windows on JDK 11	6m 24s
Client Tests	27m 22s
Replication Tests	23m 41s
Compatibility Check Java8	18m 54s
Remaining Tests	17m 16s
OWASP Dependency Check	0s
Compatibility Check Java11	19m 41s
TLS Tests	9m 34s
Compatibility Check Java17	19m 1s
StreamStorage Tests	18m 35s
Compatibility Check Java21	18m 51s
Shell tests	27s
BookKeeper CI checks completed	1s
	4h 18m 6s

Provide feedback