Prevent system autofill offering to save passwords (#5091)

Task/Issue URL:
https://app.asana.com/0/1203822806345703/1208458715174512/f

### Description
On Android 14, `importantForAutofill` is not respected so need to do
something else to stop the system autofill provider prompt offering to
save a password that our user has just manually entered or edited

### Steps to test this PR
QA-optional. But if you are curious:

- [ ] Install on Android 14 device, with Google Password Manager set as
autofill provider
- [ ] Manually add a password in our password management screen and save
it. Return to the password management list
- [ ] Verify you aren't prompted to save in Google Password Manager

Author: CDRussell

autofill/autofill-impl/src/main/java/com/duckduckgo/autofill/impl/ui/credential/management/viewing/AutofillManagementCredentialsMode.kt

@@ -23,11 +23,11 @@ import android.view.Menu
 import android.view.MenuInflater
 import android.view.MenuItem
 import android.view.View
+import android.view.autofill.AutofillManager
 import android.widget.CompoundButton
 import androidx.appcompat.app.ActionBar
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.widget.Toolbar
-import androidx.core.content.ContextCompat.startActivity
 import androidx.core.graphics.drawable.toBitmap
 import androidx.core.view.MenuProvider
 import androidx.lifecycle.Lifecycle
@@ -237,6 +237,7 @@ class AutofillManagementCredentialsMode : DuckDuckGoFragment(R.layout.fragment_a
 
     override fun onDestroyView() {
         super.onDestroyView()
+        disableSystemAutofillServiceOnPasswordField()
         resetToolbarOnExit()
         binding.removeSaveStateWatcher(saveStateWatcher)
     }
@@ -502,6 +503,9 @@ class AutofillManagementCredentialsMode : DuckDuckGoFragment(R.layout.fragment_a
 
     private fun disableSystemAutofillServiceOnPasswordField() {
         binding.passwordEditText.importantForAutofill = View.IMPORTANT_FOR_AUTOFILL_NO_EXCLUDE_DESCENDANTS
+        context?.let {
+            it.getSystemService(AutofillManager::class.java)?.cancel()
+        }
     }
 
     private fun String.convertBlankToNull(): String? = this.ifBlank { null }