Change return type and cache regex

Author: Athira M

src/main/java/com/google/firebase/remoteconfig/AndCondition.java

@@ -24,7 +24,6 @@
 import com.google.firebase.remoteconfig.internal.ServerTemplateResponse.AndConditionResponse;
 import com.google.firebase.remoteconfig.internal.ServerTemplateResponse.OneOfConditionResponse;
 
-import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -49,8 +48,8 @@ final class AndCondition {
   }
 
   @NonNull
-  List<OneOfCondition> getConditions() {
-    return new ArrayList<>(conditions);
+  ImmutableList<OneOfCondition> getConditions() {
+    return conditions;
   }
 
   AndConditionResponse toAndConditionResponse() {

src/main/java/com/google/firebase/remoteconfig/ConditionEvaluator.java

@@ -43,6 +43,7 @@ final class ConditionEvaluator {
   private static final int MAX_CONDITION_RECURSION_DEPTH = 10;
   private static final Logger logger = LoggerFactory.getLogger(ConditionEvaluator.class);
   private static final BigInteger MICRO_PERCENT_MODULO = BigInteger.valueOf(100_000_000L);
+  private static final Pattern SEMVER_PATTERN =  Pattern.compile("^[0-9]+(?:\\.[0-9]+){0,4}$");
 
   /**
    * Evaluates server conditions and assigns a boolean value to each condition.
@@ -340,7 +341,6 @@ private List<Integer> parseSemanticVersion(String versionString) {
   }
 
   private boolean validateSemanticVersion(String version) {
-    Pattern pattern = Pattern.compile("^[0-9]+(?:\\.[0-9]+){0,4}$");
-    return pattern.matcher(version).matches();
+    return SEMVER_PATTERN.matcher(version).matches();
   }
 }

src/main/java/com/google/firebase/remoteconfig/OrCondition.java

@@ -23,7 +23,6 @@
 import com.google.firebase.internal.NonNull;
 import com.google.firebase.remoteconfig.internal.ServerTemplateResponse.OneOfConditionResponse;
 import com.google.firebase.remoteconfig.internal.ServerTemplateResponse.OrConditionResponse;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.stream.Collectors;
 
@@ -46,8 +45,8 @@ public OrCondition(@NonNull List<OneOfCondition> conditions) {
   }
 
   @NonNull
-  List<OneOfCondition> getConditions() {
-    return new ArrayList<>(conditions);
+  ImmutableList<OneOfCondition> getConditions() {
+    return conditions;
   }
 
   OrConditionResponse toOrConditionResponse() {