Update dependency io.reactivex.rxjava3:rxjava to v3.1.3

Author: renovate-bot

app/build.gradle

@@ -112,7 +112,7 @@ dependencies {
     //JS engine
     implementation 'com.eclipsesource.j2v8:j2v8:6.2.0@aar'
     //Observables
-    implementation "io.reactivex.rxjava3:rxjava:3.0.4"
+    implementation "io.reactivex.rxjava3:rxjava:3.1.3"
 
     //TestFairy
     implementation 'testfairy:testfairy-android-sdk:1.9.16@aar'