Fix bug on LinearGradient's stops on Android

This patch fixes an issue reported on `react-native-community/react-native-svg`
repository that made `LinearGradient` throw an error when it
has two or more `Stop` with the same offset.

ISSUE=software-mansion/react-native-svg#385

Author: uqmessias

src/index.js

@@ -30,7 +30,7 @@ export default class ContentLoader extends Component {
                 '-2', '-1.5', '-1'
             ],
             offsets: [
-                '0', '0', '0'
+                '0.0001', '0.0002', '0.0003' // Avoid duplicate value cause error in Android
             ],
             frequence: props.duration / 2
         }
@@ -73,7 +73,14 @@ export default class ContentLoader extends Component {
             offsetValues[0] = this.offsetValueBound(newState.offsetValues[0]);
             offsetValues[1] = this.offsetValueBound(newState.offsetValues[1]);
             offsetValues[2] = this.offsetValueBound(newState.offsetValues[2]);
-            this.setState({offsets: offsetValues});
+
+            // Make sure at least two offsets is different
+            // original fix from: https://github.com/virusvn/react-native-svg-animated-linear-gradient/commit/b9558aab3bbd8f5be50204dd5cb67c9348c60fb9
+            if (offsetValues[0] !== offsetValues[1] ||
+                offsetValues[0] !==  offsetValues[2] ||
+                offsetValues[1] !== offsetValues[2]) {
+                this.setState({offsets: offsetValues});
+            }
             if (t < 1) {
                 requestAnimationFrame(this._animation);
             }