Bump BWC tests to use v5.0.2

Author: s1monw

qa/backwards-5.0/build.gradle

@@ -18,6 +18,6 @@ integTest {
   cluster {
     numNodes = 2
     numBwcNodes = 1
-    bwcVersion = "5.0.1"
+    bwcVersion = "5.0.2"
   }
 }

qa/rolling-upgrade/build.gradle

@@ -25,7 +25,7 @@ task oldClusterTest(type: RestIntegTestTask) {
     mustRunAfter(precommit)
     cluster {
         distribution = 'zip'
-        bwcVersion = '5.0.0' // TODO: either randomize, or make this settable with sysprop
+        bwcVersion = '5.0.2' // TODO: either randomize, or make this settable with sysprop
         numBwcNodes = 2
         numNodes = 2
         clusterName = 'rolling-upgrade'