fix(Logging): fix concurrency issues with logLevel (#1431)

Author: lawmicha

Amplify/Categories/Logging/LoggingCategory.swift

@@ -22,9 +22,12 @@ final public class LoggingCategory: Category {
 
     let concurrencyQueue = DispatchQueue(label: "com.amazonaws.Amplify.Logging.concurrency",
                                          target: DispatchQueue.global())
+    let lock: NSLocking = NSLock()
 
     public let categoryType = CategoryType.logging
 
+    private var _logLevel = LogLevel.error
+
     /// The global logLevel. Messages logged at a priority less than or equal to this value will be logged (e.g., if
     /// `logLevel` is set to `.info`, then messages sent at `.error`, `.warn`, and `.info` will be logged, but messages
     /// at `.debug` and `.verbose` will not be logged. The global log level is also used for the default logger
@@ -38,7 +41,18 @@ final public class LoggingCategory: Category {
     /// viewLogger.info("A view loaded") // Will not be logged
     /// networkLogger.info("A network operation started") // Will be logged
     /// ```
-    public var logLevel = LogLevel.error
+    public var logLevel: LogLevel {
+        get {
+            lock.execute {
+                _logLevel
+            }
+        }
+        set {
+            lock.execute {
+                _logLevel = newValue
+            }
+        }
+    }
 
     var configurationState = ConfigurationState.default