Enable updated accumulator variable for CEL Java by default.

PiperOrigin-RevId: 707607511

Author: jnthntatum

common/src/main/java/dev/cel/common/CelOptions.java

@@ -192,7 +192,7 @@ public static Builder newBuilder() {
         .populateMacroCalls(false)
         .retainRepeatedUnaryOperators(false)
         .retainUnbalancedLogicalExpressions(false)
-        .enableHiddenAccumulatorVar(false)
+        .enableHiddenAccumulatorVar(true)
         .enableQuotedIdentifierSyntax(false)
         // Type-Checker options
         .enableCompileTimeOverloadResolution(false)