Teeui example

This patch adds an example of a UI described using the new layout
language. It implements the layout described in the
Android Protected Confirmation Design guidelines[1] for layouts with
physical buttons. The example can be linked with the teeui_jni library
and tested with the TeeuiFramebufferizer tool.

[1]https://source.android.com/security/protected-confirmation/design

Test: make TeeuiFramebufferizer
      LD_LIBRARY_PATH=./out/host/linux-x86/lib64 TeeuiFramebufferizer
Bug: 111446692
Bug: 111451575
Change-Id: I5ebcb8a27999ea4c78c82dc5b1855a322f8c8fb0
13 files changed