Only return password for account session flow if the caller is signed
with system key and have get_password permission.

Bug: 30455516
Change-Id: I78484c59e4de1dff685ab91a0a8e7a756fffd9bf
(cherry picked from commit 9342e137c68e9d31e61b774f7a6583ed5f8353f9)
2 files changed