Support both admin role name

Support both admin role name

Depending of the installer the admin role name can be admin
or Admin.

This patch was tested:
+-------------------+------------------+------------------+----------------+
|     TEST CASE     |     PROJECT      |     DURATION     |     RESULT     |
+-------------------+------------------+------------------+----------------+
|     api_check     |     functest     |      09:60       |      PASS      |
+-------------------+------------------+------------------+----------------+

Change-Id: I99815777794cd6524213abca1f04ec84dae1e760
Signed-off-by: Valentin Boucher <valentin.boucher@kontron.com>