[System.Core] Add AesCryptoServiceProvider to the MONODROID profile.

Context: System.Security.Cryptography/AesCryptoServiceProvider.cs

Add System.Security.Cryptography.AesCryptoServiceProvider to the
MONODROID profile.

This is needed so that Aes.Create() can work.

mcs/class/System.Core/monodroid_System.Core.dll.sources

@@ -3,6 +3,7 @@
 #include dynamic_System.Core.dll.sources
 
 System/TimeZoneInfo.Android.cs
+System.Security.Cryptography/AesCryptoServiceProvider.cs
 System.Security.Cryptography/AesManaged.cs
 System.Security.Cryptography/AesTransform.cs