Release POMs in Maven Central are invalid

[janhicken]

Hello,

the POMs of endpoints-management-config and endpoints-management-protos from versions >= 1.0.12 from Maven Central are invalid. This is because of a150982 which removed the version spec of some Protobuf dependencies. This results in missing versions in the generated POM files which in turn lead to missing transitive dependencies when having the Endpoints Management framework as a dependency.

Here are the corresponding error messages from the Maven debug log:

[WARNING] The POM for com.google.endpoints:endpoints-management-config:jar:1.0.13 is invalid, transitive dependencies (if any) will not be available: 2 problems were encountered while building the effective model for com.google.endpoints:endpoints-management-config:1.0.13
[ERROR] 'dependencies.dependency.version' for com.google.protobuf:protobuf-java:jar is missing. @ 
[ERROR] 'dependencies.dependency.version' for com.google.protobuf:protobuf-java-util:jar is missing. @ 

[WARNING] The POM for com.google.endpoints:endpoints-management-protos:jar:1.0.13 is invalid, transitive dependencies (if any) will not be available: 3 problems were encountered while building the effective model for com.google.endpoints:endpoints-management-protos:1.0.13
[ERROR] 'dependencies.dependency.version' for com.google.protobuf:protobuf-java:jar is missing. @ 
[ERROR] 'dependencies.dependency.version' for io.grpc:grpc-stub:jar is missing. @ 
[ERROR] 'dependencies.dependency.version' for io.grpc:grpc-protobuf:jar is missing. @