Reland^2: Use "gfxstream" namespace

This reverts commit 04c96274efbb8c845f7a4a8609f85fd4c6982ef3.

Reland adds in aosp/2516595 which was only built on the "full"
target and removes namespace around window methods to satisfy
MacOS build.

Bug: b/271464937
Test: android build
Test: cmake build
Change-Id: Iaf9c35e89938613e998110641a5112872e079c57
diff --git a/system/vulkan_enc/AndroidHardwareBuffer.h b/system/vulkan_enc/AndroidHardwareBuffer.h
index 2a6e182..9c9cb94 100644
--- a/system/vulkan_enc/AndroidHardwareBuffer.h
+++ b/system/vulkan_enc/AndroidHardwareBuffer.h
@@ -24,7 +24,8 @@
 
 class Gralloc;
 
-namespace goldfish_vk {
+namespace gfxstream {
+namespace vk {
 
 uint64_t
 getAndroidHardwareBufferUsageFromVkUsage(
@@ -58,4 +59,5 @@
     VkDeviceSize allocationInfoAllocSize,
     struct AHardwareBuffer **out);
 
-} // namespace goldfish_vk
+}  // namespace vk
+}  // namespace gfxstream