Bump okhttp from 3.9.1 to 3.11.0 (#960)

Bumps [okhttp](https://github.com/square/okhttp) from 3.9.1 to 3.11.0.
- [Release notes](https://github.com/square/okhttp/releases)
- [Changelog](https://github.com/square/okhttp/blob/master/CHANGELOG.md)
- [Commits](https://github.com/square/okhttp/compare/parent-3.9.1...parent-3.11.0

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

mobile/build.gradle

@@ -103,7 +103,7 @@ dependencies {
     implementation "com.android.support:design:27.1.1"
     implementation 'com.android.support:multidex:1.0.3'
     implementation 'org.jmdns:jmdns:3.5.3'
-    implementation 'com.squareup.okhttp3:okhttp:3.9.1'
+    implementation 'com.squareup.okhttp3:okhttp:3.11.0'
     implementation 'com.larswerkman:HoloColorPicker:1.5'
     implementation 'com.github.BigBadaboom:androidsvg:3511e136498da94018ef9fa438895984ea9b99db'
     implementation 'com.github.apl-devs:appintro:v4.2.2'