[FAB-15119] Fix BYFN with Java chaincode

The issue is that BYFN passes "Init" function while the
sample Java chaincode checks for "init" function.

Within the init function, there is no need to check the function
argument that is passed in. The sample Go chaincode and Node.js
chaincode do not check the function argument. This change makes
sample Java chaincode behave the same way.

Change-Id: I802978e1276e92a3d420b3f4a391ff66a352d321
Signed-off-by: David Enyeart <enyeart@us.ibm.com>

chaincode/abstore/java/src/main/java/org/hyperledger/fabric-samples/ABstore.java

@@ -24,10 +24,6 @@ public class ABstore extends ChaincodeBase {
  public Response init(ChaincodeStub stub) {
  try {
  _logger.info("Init java simple chaincode");
- String func = stub.getFunction();
- if (!func.equals("init")) {
- return newErrorResponse("function other than init is not supported");
- }
  List<String> args = stub.getParameters();
  if (args.size() != 4) {
  newErrorResponse("Incorrect number of arguments. Expecting 4");