How to grant execution rights on DBMS packages to a PDB user?
By default, noone is granted the EXECUTE privilege on DBMS_LOCK with grant option. Even the DBA role does not have the grant option. test1admin has access to DBMS_LOCK, but test1admin is not authorized to grant privileges on DBMS_LOCK to additional users. You need to connect as SYS to grant privileges on DBMS_LOCK to additional users.

Connect to the CDB root as SYS and switch to your pluggable database:

sqlplus / as sysdba
alter session set container = test1;


Or connect to the PDB directly:

sqlplus sys@test1 as sysdba


And issue the grant:

grant execute on dbms_lock to test1;


If you want test1admin to be able to grant privileges to DBMS_LOCK to others, then as SYS, issue the below:

grant execute on dbms_lock to test1admin with grant option;