nativewindow: Misc. improvements for AHardwareBuffer Rust wrapper

Changes include:

  - Rename AHardwareBuffer to HardwareBuffer
  - Expose AHardwareBuffer as a raw pointer type
  - Making HardwareBuffer Send
  - HardwareBuffer now derives Debug, PartialEq and Eq
  - Use NonNull instead of a *mut pointer
  - Adding an into_raw function to match from_raw
  - Adding a Clone impl that acquires a ref

Bug: 296449936, 296100790
Test: atest libnativewindow_rs-internal_test
Change-Id: Iaf916fabe49190f47abd1a9ed34afdb76fd20e40
diff --git a/libs/bufferstreams/rust/src/lib.rs b/libs/bufferstreams/rust/src/lib.rs
index 87f3104..5964281 100644
--- a/libs/bufferstreams/rust/src/lib.rs
+++ b/libs/bufferstreams/rust/src/lib.rs
@@ -159,7 +159,7 @@
 /// Struct used to contain the buffer.
 pub struct Frame {
     /// A handle to the C buffer interface.
-    pub buffer: AHardwareBuffer,
+    pub buffer: HardwareBuffer,
     /// The time at which the buffer was dispatched.
     pub present_time: Instant,
     /// A fence used for reading/writing safely.