Make intraline background transparent when the row is out of focus range

This is to make the intraline background consistent with the row background.

Screenshot(before): https://screenshot.googleplex.com/9zhTgJKmWcogh3R
Screenshot (after): https://screenshot.googleplex.com/MXbXpqxSKaom8FM

Change-Id: Id074683fb161ea6e8e9e8b53396ed9463776c90a
Release-Notes: skip
Google-Bug-Id: b/345126277

polygerrit-ui/app/embed/diff/gr-diff/gr-diff-styles.ts

diff --git a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-styles.ts b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-styles.ts
index 98a2093..2913fc8 100644
--- a/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-styles.ts
+++ b/polygerrit-ui/app/embed/diff/gr-diff/gr-diff-styles.ts
@@ -369,6 +369,9 @@
     background-color: var(--dark-add-highlight-color);
     &:has(.is-out-of-focus-range) {
       background-color: transparent;
+      .intraline {
+        background-color: transparent;
+      }
     }
   }
   gr-diff-row td.content.add div.contentText,
@@ -376,6 +379,9 @@
     background-color: var(--light-add-highlight-color);
     &:has(.is-out-of-focus-range) {
       background-color: transparent;
+      .intraline {
+        background-color: transparent;
+      }
     }
   }
   /* If there are no intraline info, consider everything changed */