Fix certificate management tabbing

- Adds focus to "choose file" button when replacing certificate
- Adds input-file.scss to elements

Tested:
- Passes DAP
- Tabs correctly in all browsers

Signed-off-by: Dixsie Wolmers <dixsiew@gmail.com>
Change-Id: I48c61f4176bc3e3fe55425dafc79e8f2edb934b2
diff --git a/app/common/styles/elements/index.scss b/app/common/styles/elements/index.scss
index 0588813..66a2877 100644
--- a/app/common/styles/elements/index.scss
+++ b/app/common/styles/elements/index.scss
@@ -3,6 +3,7 @@
 @import "status";
 @import "alerts";
 @import "inline-confirm";
+@import "input-file";
 @import "accordion";
 @import "loader";
 @import "content-search";