[fenix] Close https://github.com/mozilla-mobile/fenix/issues/25449: Use "Enter search terms" as hint when using application search engine

app/src/main/java/org/mozilla/fenix/search/toolbar/ToolbarView.kt

@@ -10,6 +10,7 @@ import android.graphics.drawable.BitmapDrawable
 import androidx.annotation.VisibleForTesting
 import androidx.appcompat.content.res.AppCompatResources
 import androidx.core.content.ContextCompat
+import mozilla.components.browser.state.search.SearchEngine
 import mozilla.components.browser.toolbar.BrowserToolbar
 import mozilla.components.support.ktx.android.content.getColorFromAttr
 import mozilla.components.support.ktx.android.content.res.resolveAttribute
@@ -143,6 +144,13 @@ class ToolbarView(
 
         val searchEngine = searchState.searchEngineSource.searchEngine
 
+        when (searchEngine?.type) {
+            SearchEngine.Type.APPLICATION ->
+                view.edit.hint = context.getString(R.string.application_search_hint)
+            else ->
+                view.edit.hint = context.getString(R.string.search_hint)
+        }
+
         if (!settings.showUnifiedSearchFeature && searchEngine != null) {
             val iconSize =
                 context.resources.getDimensionPixelSize(R.dimen.preference_icon_drawable_size)

app/src/main/res/values/strings.xml

@@ -16,6 +16,8 @@
     <string name="content_description_disable_private_browsing_button">Disable private browsing</string>
     <!-- Placeholder text shown in the search bar before a user enters text -->
     <string name="search_hint">Search or enter address</string>
+    <!-- Placeholder text shown in the search bar when using application search engines -->
+    <string name="application_search_hint">Enter search terms</string>
     <!-- No Open Tabs Message Description -->
     <string name="no_open_tabs_description">Your open tabs will be shown here.</string>
     <!-- No Private Tabs Message Description -->

app/src/test/java/org/mozilla/fenix/search/toolbar/ToolbarViewTest.kt

@@ -13,6 +13,7 @@ import io.mockk.impl.annotations.MockK
 import io.mockk.mockk
 import io.mockk.spyk
 import io.mockk.verify
+import mozilla.components.browser.state.search.SearchEngine
 import mozilla.components.browser.toolbar.BrowserToolbar
 import mozilla.components.browser.toolbar.edit.EditToolbar
 import mozilla.components.concept.engine.Engine
@@ -45,6 +46,7 @@ class ToolbarViewTest {
             mockk {
                 every { name } returns "Search Engine"
                 every { icon } returns testContext.getDrawable(R.drawable.ic_search)!!.toBitmap()
+                every { type } returns SearchEngine.Type.BUNDLED
             }
         ),
         defaultEngine = null,