Revert "[CrOS Settings] Fix number alignment on PIN keyboard."

This reverts commit 05103cd7.

Reason for revert: Broke OOBE pin keyboard, reverting in favor of CL:1862914. See bug for details

Original change's description:
> [CrOS Settings] Fix number alignment on PIN keyboard.
> 
> Each button on the keypad includes space for a number as well as the
> letters which represent the numbers (e.g., "ABC" for 2, "DEF" for 3).
> However, since 1 does not have any associated letters, its alignment was
> incorrect and noticeably different from the rest of the buttons.
> 
> This CL fixes this alignment issue by aligning the number to the top of
> the button and the letters to the bottom of the button.
> 
> Fixed: 1004974
> TBR: stevenjb@chromium.org
> Change-Id: I9be7be402b853cbf6ba76985151f77a0696ac13b
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1854638
> Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
> Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
> Auto-Submit: Kyle Horimoto <khorimoto@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#704900}

TBR=stevenjb@chromium.org,khorimoto@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: Ida1e2ecc148859f38ae4b6075daa5a412453d707
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1863793Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Commit-Queue: Roman Sorokin [CET] <rsorokin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706345}

ui/webui/resources/cr_components/chromeos/quick_unlock/pin_keyboard.html

@@ -133,17 +133,9 @@
 
       .digit-button inner-text {
         font-family: 'Roboto';
-        position: absolute;
       }
 
-      .number {
-        color: var(--pin-keyboard-number-color, var(--paper-blue-grey-700));
-        font-size: 18px;
-        top: 0;
-      }
-
-      .letter {
-        bottom: 0;
+      inner-text.letter {
         color: var(--pin-keyboard-letter-color, var(--google-grey-700));
         font-size: 12px;
         margin-top: 8px;
@@ -151,6 +143,12 @@
         @apply --pin-keyboard-digit-button-letter;
       }
 
+      .number {
+        color: var(--pin-keyboard-number-color, var(--paper-blue-grey-700));
+        font-size: 18px;
+        height: 16px;
+      }
+
       #pinInput {
         --cr-input-error-display: none;
         --cr-input-input: {