Fix to only localize the primary localization and not the fall-throug…

Sources/MapboxMaps/Style/Style+Localization.swift

@@ -85,7 +85,7 @@ extension Style {
 
         if var stringExpression = String(data: try JSONEncoder().encode(symbolLayer.textField), encoding: .utf8),
            stringExpression != "null" {
-            stringExpression.updateExpression(replacement: replacement, regex: expressionCoalesce)
+            stringExpression.updateOnceExpression(replacement: replacement, regex: expressionCoalesce)
             stringExpression.updateExpression(replacement: replacement, regex: expressionAbbr)
 
             // Turn the new json string back into an Expression
@@ -113,4 +113,19 @@ extension String {
                                               range: range,
                                               withTemplate: replacement)
     }
+
+    /// Updates string once using the first occurrence of a regex
+    /// - Parameters:
+    ///   - replacement: New string to replace the matched pattern
+    ///   - regex: The regex pattern that will be matched for replacement
+    internal mutating func updateOnceExpression(replacement: String, regex: NSRegularExpression) {
+        var range = NSRange(location: 0, length: self.count)
+        range = regex.rangeOfFirstMatch(in: self, options: [], range: range)
+        if (range.lowerBound == NSNotFound)
+            return
+        self = regex.stringByReplacingMatches(in: self,
+                                              options: [],
+                                              range: range,
+                                              withTemplate: replacement)
+    }
 }