Limit number of recents entries for an app to maxRecents allowed.

Regression in the API caused by the fixes for b/28293748 and b/25460953
which prevented the task entries from been trimmed if the task don't
have the same intent filter (additional documents launched will normally
have different intent action/filter than the base activity) or it allows
multiple task entries.
We now trim when we go over the maxRecents allowed in both cases.

Bug: 30645949
Bug: 28293748
Bug: 25460953
Change-Id: I74c8ecc38f72a5d03c213dea8d3e62261d42f8f6

services/core/java/com/android/server/am/RecentTasks.java

@@ -653,12 +653,17 @@ class RecentTasks extends ArrayList<TaskRecord> {
                             && task.realActivity.equals(tr.realActivity);
                     // If the document is open in another app or is not the same
                     // document, we don't need to trim it.
-                    if (!sameActivity || !sameIntentFilter || multiTasksAllowed) {
+                    if (!sameActivity) {
                         continue;
                     // Otherwise only trim if we are over our max recents for this task
-                    } else if (maxRecents > 0 && !doTrim) {
+                    } else if (maxRecents > 0) {
                         --maxRecents;
-                        continue;
+                        if (!doTrim || !sameIntentFilter || multiTasksAllowed) {
+                            // We don't want to trim if we are not over the max allowed entries and
+                            // the caller doesn't want us to trim, the tasks are not of the same
+                            // intent filter, or multiple entries fot the task is allowed.
+                            continue;
+                        }
                     }
                     // Hit the maximum number of documents for this task. Fall through
                     // and remove this document from recents.