[FAB-15038] longer name for 'pr' variable
[FAB-15038] longer name for 'pr' variable

Apply the rule, the farther the declaration of a variable from its use,
the more descriptive the name should be.

In this case, pr (platformRegistry) was used hundreds of lines away from
its declaration.

Change-Id: I3d2b8d6497203fc11ebf4137564954a33e7d9baa
Signed-off-by: Matthew Sykes <89c6e4c9c1046731a9c37abefc223a83de36a5d9@us.ibm.com>

muralisrini/fabric,binhn/fabric,jimthematrix/fabric,binhn/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,muralisrini/fabric,stemlending/fabric,muralisrini/fabric,hyperledger/fabric,jimthematrix/fabric,manish-sethi/fabric,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,manish-sethi/fabric-sidedb,hyperledger/fabric,stemlending/fabric,manish-sethi/fabric,stemlending/fabric,binhn/fabric,manish-sethi/fabric-sidedb,stemlending/fabric