build(deps): bump nav_version in /15_services/android

Bumps `nav_version` from 2.7.7 to 2.8.4.

Updates `androidx.navigation:navigation-fragment-ktx` from 2.7.7 to 2.8.4

Updates `androidx.navigation:navigation-ui-ktx` from 2.7.7 to 2.8.4

---
updated-dependencies:
- dependency-name: androidx.navigation:navigation-fragment-ktx
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: androidx.navigation:navigation-ui-ktx
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

15_services/android/app/build.gradle

@@ -58,7 +58,7 @@ dependencies {
     def activity_version = "1.9.3"
     def lifecycle_version = "2.8.7"
     def mdc_version = "1.12.0"
-    def nav_version = "2.7.7"
+    def nav_version = "2.8.4"
     def room_version = "2.6.1"
     def firebase_version = "33.5.1"
     def glide_version = "4.16.0"