Return to manual slot use instead of slot generation

ION memory increase in composer process due to slot generation.
Revert to old slot generation for BufferQueue

Bug: 127655433
Test: build, boot, HwcBufferCacheTest
Change-Id: Ifbb5747a7878aef97c92ba09e2dc72d663d78066
diff --git a/services/surfaceflinger/BufferQueueLayer.cpp b/services/surfaceflinger/BufferQueueLayer.cpp
index e4179ee..d3b36fe 100644
--- a/services/surfaceflinger/BufferQueueLayer.cpp
+++ b/services/surfaceflinger/BufferQueueLayer.cpp
@@ -361,8 +361,12 @@
 
     uint32_t hwcSlot = 0;
     sp<GraphicBuffer> hwcBuffer;
+
+    // INVALID_BUFFER_SLOT is used to identify BufferStateLayers.  Default to 0
+    // for BufferQueueLayers
+    int slot = (mActiveBufferSlot == BufferQueue::INVALID_BUFFER_SLOT) ? 0 : mActiveBufferSlot;
     (*outputLayer->editState().hwc)
-            .hwcBufferCache.getHwcBuffer(mActiveBuffer, &hwcSlot, &hwcBuffer);
+            .hwcBufferCache.getHwcBuffer(slot, mActiveBuffer, &hwcSlot, &hwcBuffer);
 
     auto acquireFence = mConsumer->getCurrentFence();
     auto error = hwcLayer->setBuffer(hwcSlot, hwcBuffer, acquireFence);