Remove legacy disable triple buffering config

The config changes the dequeue limit of BQ (setMaxDequeuedBufferCount) from 2 to 1,  decreasing the default size of the queue from (3 to 2).
Some of the motivations behind this change include:
- not applicable in most scenarios since producers in the system override this
- breaks async mode, not well tested in other scenarios
- simplifying some of the implementation and removes a configuration/flag.

Clients can still manually call setMaxDequeuedBufferCount if they wish.

Test: presubmit
Fixes: 182314340
Change-Id: Iea88e8a795b91ff325610cfb1eefbcfe6e434841
diff --git a/services/surfaceflinger/BufferQueueLayer.cpp b/services/surfaceflinger/BufferQueueLayer.cpp
index 63dd25f..c0ce84f 100644
--- a/services/surfaceflinger/BufferQueueLayer.cpp
+++ b/services/surfaceflinger/BufferQueueLayer.cpp
@@ -521,10 +521,7 @@
     mConsumer->setContentsChangedListener(mContentsChangedListener);
     mConsumer->setName(String8(mName.data(), mName.size()));
 
-    // BufferQueueCore::mMaxDequeuedBufferCount is default to 1
-    if (!mFlinger->isLayerTripleBufferingDisabled()) {
-        mProducer->setMaxDequeuedBufferCount(2);
-    }
+    mProducer->setMaxDequeuedBufferCount(2);
 }
 
 status_t BufferQueueLayer::setDefaultBufferProperties(uint32_t w, uint32_t h, PixelFormat format) {