ErrorProne - enable NarrowCalculation check

Author: stankiewicz

buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy

@@ -1556,7 +1556,6 @@ class BeamModulePlugin implements Plugin<Project> {
             "Finalize",
             "JUnitIncompatibleType",
             "MockNotUsedInProduction",
-            "NarrowCalculation",
             "NullableTypeParameter",
             "NullableWildcard",
             "SuperCallToObjectMethod",

sdks/java/testing/nexmark/src/main/java/org/apache/beam/sdk/nexmark/sources/generator/GeneratorConfig.java

@@ -104,7 +104,7 @@ public GeneratorConfig(
       // Scale maximum down to avoid overflow in getEstimatedSizeBytes.
       this.maxEvents =
           Long.MAX_VALUE
-              / (PROPORTION_DENOMINATOR
+              / ((long) PROPORTION_DENOMINATOR
                   * Math.max(
                       Math.max(configuration.avgPersonByteSize, configuration.avgAuctionByteSize),
                       configuration.avgBidByteSize));