Assigned SerializedName for GroupReport fields

xxclient/src/main/java/io/elixxir/xxclient/models/GroupReport.kt

 package io.elixxir.xxclient.models
 
+import com.google.gson.annotations.SerializedName
+
 data class GroupReport(
+    @SerializedName("Id")
     val id: String,
+    @SerializedName("Rounds")
     val rounds: List<Long>,
+    @SerializedName("RoundURL")
     val roundUrl: String,
+    @SerializedName("Status")
     val status: Long
 ) : BindingsModel
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