Getting OutOfMemoryException in Xamarin
I would increase your build heap size.
Right click your Android Project > Properties > Android Options > Advanced > Java Max Heap Size.
The selected answer lead me in the right direction, but for Visual Studio 2017, the screen looks like:
For visual studio 2015 right click Project --> Properties --> Android Options --> Advanced and heap size there.
If you want to increase Heap size of your application (not the build process) you can set this in your AndroidManifest.xml:
<application android:largeHeap="true"></application>