Bump Newtonsoft.Json from 6.0.4 to 13.0.1 in /src/MyHealth.Client.Droid

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 6.0.4 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](https://github.com/JamesNK/Newtonsoft.Json/compare/6.0.4...13.0.1)

---
updated-dependencies:
- dependency-name: Newtonsoft.Json
  dependency-type: direct:production
...

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

src/MyHealth.Client.Droid/packages.config

@@ -20,7 +20,7 @@
   <package id="MvvmCross.HotTuna.Plugin.PictureChooser" version="4.0.0-beta3" targetFramework="monoandroid5" />
   <package id="MvvmCross.HotTuna.Plugin.Visibility" version="4.0.0-beta3" targetFramework="monoandroid5" />
   <package id="MvvmCross.HotTuna.StarterPack" version="4.0.0-beta3" targetFramework="monoandroid5" />
-  <package id="Newtonsoft.Json" version="6.0.4" targetFramework="monoandroid5" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="monoandroid5" />
   <package id="Rx-Core" version="2.2.5" targetFramework="monoandroid5" />
   <package id="Rx-Interfaces" version="2.2.5" targetFramework="monoandroid5" />
   <package id="Rx-Linq" version="2.2.5" targetFramework="monoandroid5" />