Fix JS selector (#6992)

Task/Issue URL:
https://app.asana.com/1/137249556945/project/1157893581871903/task/1211730035278177?focus=true

### Description
Fix JS injection for text selector in Duck.ai

### Steps to test this PR

_First open_
- [x] Fresh install, open Duck.ai without a prompt
- [x] Verify Terms and Conditions dialog appears
- [x] Accept them
- [x] Verify Keyboard doesn’t appear
- [x] Close Duck.ai (don’t hide the tips, we need them later)

_Keyboard doesn’t open when Tips present_
- [x] Open Duck.ai without a prompt
- [x] Verify keyboard doesn’t open
- [x] Verify Tips are present
- [x] Hide the tips
- [x] Verify keyboard doesn’t appear
- [x] Close Duck.ai

_Keyboard opens when Tips are not present_
- [x] Open Duck.ai without a prompt
- [x] Verify keyboard opens

_Auto prompt_
- [x] Open Duck.ai with a prompt
- [x] Verify keyboard doesn’t open

Author: malmstein

duckchat/duckchat-impl/src/main/java/com/duckduckgo/duckchat/impl/helper/DuckChatJSHelper.kt

@@ -152,7 +152,7 @@ class RealDuckChatJSHelper @Inject constructor(
     ): JsCallbackData {
         val jsonPayload =
             JSONObject().apply {
-                val jsCall = "document.getElementsByName($selector)[0]?.focus();"
+                val jsCall = "document.getElementsByName('$selector')[0]?.focus();"
                 put(SELECTOR, jsCall)
                 put(SUCCESS, true)
                 put(ERROR, "")

duckchat/duckchat-impl/src/test/kotlin/com/duckduckgo/duckchat/impl/helper/RealDuckChatJSHelperTest.kt

@@ -465,7 +465,7 @@ class RealDuckChatJSHelperTest {
         val result = testee.processJsCallbackMessage(featureName, method, id, data)
 
         val expectedPayload = JSONObject().apply {
-            put("selector", "document.getElementsByName('user-prompt')[0]?.focus();")
+            put("selector", "document.getElementsByName(''user-prompt'')[0]?.focus();")
             put("success", true)
             put("error", "")
         }