Revert "Allow GRALLOC_USAGE_HW_FB as usage hint for UBWC."

This reverts commit 766d1fa40c37eaaa6afbaaa14cb3e2be56253745.

Reason for revert: Breaks camera preview (b/119242746)

Change-Id: I17743f478dcaae9a4cfbbcacf9b16d90e3501286
(cherry picked from commit cb8ad10ab1625be985aff72073764db39d3e834c)
diff --git a/gralloc/gr_utils.cpp b/gralloc/gr_utils.cpp
index 870d018..48d8bb5 100644
--- a/gralloc/gr_utils.cpp
+++ b/gralloc/gr_utils.cpp
@@ -558,9 +558,8 @@
   // Allow UBWC, if an OpenGL client sets UBWC usage flag and GPU plus MDP
   // support the format. OR if a non-OpenGL client like Rotator, sets UBWC
   // usage flag and MDP supports the format.
-  if (IsUBwcSupported(format)) {
-    bool enable =
-        (usage & GRALLOC_USAGE_PRIVATE_ALLOC_UBWC) | (usage & BufferUsage::COMPOSER_CLIENT_TARGET);
+  if ((usage & GRALLOC_USAGE_PRIVATE_ALLOC_UBWC) && IsUBwcSupported(format)) {
+    bool enable = true;
     // Query GPU for UBWC only if buffer is intended to be used by GPU.
     if ((usage & BufferUsage::GPU_TEXTURE) || (usage & BufferUsage::GPU_RENDER_TARGET)) {
       if (AdrenoMemInfo::GetInstance()) {
@@ -970,8 +969,6 @@
   int is_ubwc_enabled = IsUBwcEnabled(info.format, info.usage);
   if (!is_ubwc_enabled) {
     adreno_usage &= ~(GRALLOC_USAGE_PRIVATE_ALLOC_UBWC);
-  } else {
-    adreno_usage |= GRALLOC_USAGE_PRIVATE_ALLOC_UBWC;
   }
 
   // Call adreno api for populating metadata blob