Rename CommandWriter to CommandWriterBase

CommandWriter will be used as a base class in extensions of HWC. Renamed
for consistency.

Bug: 33297385
Test: Compiled
Change-Id: Iabe59f37157062961b916d55108cb9f4fb792619
diff --git a/graphics/composer/2.1/default/IComposerCommandBuffer.h b/graphics/composer/2.1/default/IComposerCommandBuffer.h
index 65e7799..fb78ef8 100644
--- a/graphics/composer/2.1/default/IComposerCommandBuffer.h
+++ b/graphics/composer/2.1/default/IComposerCommandBuffer.h
@@ -52,16 +52,16 @@
 
 // This class helps build a command queue.  Note that all sizes/lengths are in
 // units of uint32_t's.
-class CommandWriter {
+class CommandWriterBase {
 public:
-    CommandWriter(uint32_t initialMaxSize)
+    CommandWriterBase(uint32_t initialMaxSize)
         : mDataMaxSize(initialMaxSize)
     {
         mData = std::make_unique<uint32_t[]>(mDataMaxSize);
         reset();
     }
 
-    ~CommandWriter()
+    virtual ~CommandWriterBase()
     {
         reset();
     }