Bug 1924094 - Wait for add-on list to be loaded and download to be finalised in UI tests r=aaronmt,ohorvath

While trying to address the issues encountered lately on all branches in some add-ons related UI tests, I've added:

  - A wait for the download list to be properly being displayed (this should also improve syncing and not falsely swipe on the list while the featured add-ons aren't yet loaded)
  - A wait for the add-ons download overlay to be gone, to be able to properly verify the add-on permission prompt.

The following UI tests successfully passed 200x on both API 30 and 34:

verifyUBlockWorksInNormalModeTest
verifyAddonsCanBeUninstalledTest
verifyUBlockWorksInPrivateModeTest

Differential Revision: https://phabricator.services.mozilla.com/D225350

UltraBlame original commit: d0f8243c3b3c8f6ab5d52d6e4f791b9652af49e6

Author: marco-c

mobile/android/fenix/app/src/androidTest/java/org/mozilla/fenix/ui/SettingsAddonsTest.kt

@@ -440,6 +440,9 @@ add_ons_list
 )
 )
 {
+waitForAddonsListProgressBarToBeGone
+(
+)
 clickInstallAddon
 (
 addonName

mobile/android/fenix/app/src/androidTest/java/org/mozilla/fenix/ui/robots/SettingsSubMenuAddonsManagerRobot.kt

@@ -405,6 +405,30 @@ helpers
 .
 MatcherHelper
 .
+assertUIObjectIsGone
+import
+org
+.
+mozilla
+.
+fenix
+.
+helpers
+.
+MatcherHelper
+.
+itemWithResId
+import
+org
+.
+mozilla
+.
+fenix
+.
+helpers
+.
+MatcherHelper
+.
 itemWithResIdContainingText
 import
 org
@@ -549,6 +573,48 @@ exists
 shouldBeDisplayed
 )
 fun
+waitForAddonsListProgressBarToBeGone
+(
+)
+=
+assertUIObjectIsGone
+(
+itemWithResId
+(
+"
+packageName
+:
+id
+/
+add_ons_progress_bar
+"
+)
+waitingTime
+=
+waitingTimeLong
+)
+fun
+waitForAddonsDownloadOverlayToBeGone
+(
+)
+=
+assertUIObjectIsGone
+(
+itemWithResId
+(
+"
+packageName
+:
+id
+/
+addonProgressOverlay
+"
+)
+waitingTime
+=
+waitingTimeLong
+)
+fun
 verifyAddonDownloadOverlay
 (
 )
@@ -633,6 +699,9 @@ addonName
 String
 )
 {
+waitForAddonsDownloadOverlayToBeGone
+(
+)
 mDevice
 .
 waitNotNull
@@ -1105,6 +1174,9 @@ openThreeDotMenu
 .
 openAddonsManagerMenu
 {
+waitForAddonsListProgressBarToBeGone
+(
+)
 scrollToAddon
 (
 addonName
@@ -1975,6 +2047,9 @@ openThreeDotMenu
 .
 openAddonsManagerMenu
 {
+waitForAddonsListProgressBarToBeGone
+(
+)
 clickInstallAddon
 (
 addonName
@@ -2014,6 +2089,9 @@ openThreeDotMenu
 .
 openAddonsManagerMenu
 {
+waitForAddonsListProgressBarToBeGone
+(
+)
 clickInstallAddon
 (
 addonName