fix(android): avoid crashes from concurrent native resource releases (#204)

Author: valdio

android/src/main/java/com/hieuvp/fingerprint/ReactNativeFingerprintScannerModule.java

@@ -210,7 +210,7 @@ public void authenticate(String title, String subtitle, String description, Stri
     }
 
     @ReactMethod
-    public void release() {
+    public synchronized void release() {
         if (requiresLegacyAuthentication()) {
             getFingerprintIdentify().cancelIdentify();
             mFingerprintIdentify = null;