sdm: Add support for LINEAR_FORMAT metadata operation

1. Define LINEAR_FORMAT operation in MetaData.
2. VENUS ouput buffer is linear for NV12_UBWC Interlaced video playback.
   So Video module performs LINEAR_FORMAT operation to set "linearFormat"
   metadata member to NV12 linear format in case of Interlaced video.
3. Handle LINEAR_FORMAT metadata operation in HWC wrapper and gralloc.

CRs-Fixed: 855474

Change-Id: I77dd72bec26f225de75adb6c214ccd90db239e3e
diff --git a/libgralloc/mapper.cpp b/libgralloc/mapper.cpp
index cf365ce..3cfdc55 100644
--- a/libgralloc/mapper.cpp
+++ b/libgralloc/mapper.cpp
@@ -440,6 +440,10 @@
                     return res;
                 }
                 *flag = hnd->flags & private_handle_t::PRIV_FLAGS_UBWC_ALIGNED;
+                MetaData_t *metadata = (MetaData_t *)hnd->base_metadata;
+                if (metadata && (metadata->operation & LINEAR_FORMAT)) {
+                    *flag = 0;
+                }
                 res = 0;
             } break;