Use new AndroidUnwinder object.

Replace libbacktrace with the new AndroidUnwinder object.

Bug: 120606663

Test: Ran unit tests.
Test: Added call of UnwindMainThreadStack() in DebugRebootLogging()
Test: and verified unwind data is logged properly.
Change-Id: Ia724f9485377d6d2c894283242a3c5653bf82768
diff --git a/init/Android.bp b/init/Android.bp
index dd67d04..f91265e 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -178,7 +178,6 @@
         "update_metadata-protos",
     ],
     shared_libs: [
-        "libbacktrace",
         "libbase",
         "libbootloader_message",
         "libcrypto",
@@ -195,6 +194,7 @@
         "libprocessgroup",
         "libprocessgroup_setup",
         "libselinux",
+        "libunwindstack",
         "libutils",
         "libziparchive",
     ],
@@ -352,7 +352,6 @@
         "libgsi",
         "liblzma",
         "libunwindstack_no_dex",
-        "libbacktrace_no_dex",
         "libmodprobe",
         "libext2_uuid",
         "libprotobuf-cpp-lite",