Update 3DS2 SDK to 1.2.1 (#1420)

Author: mshafrir-stripe

stripe/build.gradle

@@ -17,7 +17,7 @@ dependencies {
     // Api for this import because we use reflection to alter TextInputLayout
     api "com.android.support:design:28.0.0"
 
-    implementation "com.stripe:stripe-3ds2-android:1.2.0"
+    implementation "com.stripe:stripe-3ds2-android:1.2.1"
 
     javadocDeps "com.android.support:support-annotations:28.0.0"
     javadocDeps "com.android.support:appcompat-v7:28.0.0"