[nullsafe] Add missing `android.os.Build` string constants (#1402)

Summary:
All of those constants are backed by `android.os.Build.getString()` method, and always use the static string constant `android.os.Build.UNKNOWN` as fallback.
Here is the code in latest master:
https://android.googlesource.com/platform/frameworks/base/+/refs/heads/master/core/java/android/os/Build.java#1342
Introduced and unchanged since 2009
9066cfe988/core/java/android/os/Build.java (82)

I think it's safe to say that all of those constants are null safe.

Please see [CONTRIBUTING.md](./CONTRIBUTING.md) for how to set up your development environment and run tests.

Pull Request resolved: https://github.com/facebook/infer/pull/1402

Reviewed By: jvillard

Differential Revision: D26750342

Pulled By: mityal

fbshipit-source-id: d7a9c94b7

infer/src/nullsafe/modelTables.ml

@@ -782,14 +782,21 @@ let field_nullability =
   ; ("android.opengl.EGL14.EGL_NO_DISPLAY", o)
   ; ("android.opengl.EGL14.EGL_NO_SURFACE", o)
   ; ("android.os.Bundle.EMPTY", o)
-  ; ("android.os.Build.BRAND", o)
   ; ("android.os.Build.BOARD", o)
+  ; ("android.os.Build.BOOTLOADER", o)
+  ; ("android.os.Build.BRAND", o)
   ; ("android.os.Build.DEVICE", o)
   ; ("android.os.Build.DISPLAY", o)
   ; ("android.os.Build.FINGERPRINT", o)
   ; ("android.os.Build.HARDWARE", o)
+  ; ("android.os.Build.HOST", o)
+  ; ("android.os.Build.ID", o)
   ; ("android.os.Build.MANUFACTURER", o)
+  ; ("android.os.Build.MODEL", o)
   ; ("android.os.Build.PRODUCT", o)
+  ; ("android.os.Build.TAGS", o)
+  ; ("android.os.Build.TYPE", o)
+  ; ("android.os.Build.USER", o)
   ; ("android.os.Build.SERIAL", o)
   ; ("android.os.Build.SUPPORTED_ABIS", o)
   ; ( "android.os.Message.obj"