graphics: make mapper default impl a header library

Reimplement the default impl as a header-only library,
android.hardware.graphics.mapper@2.0-passthrough, based on the HAL
support library.

Effectively, this renames Gralloc[01]Mapper to Gralloc[01]Hal, and
make adjustments here and there to meet the requirements of the HAL
support library.  This also adds GrallocLoader to load either of
Gralloc[01]Hal and create an IMapper instance.

libgrallocmapperincludes is renamed to follow the new naming and
include path conventions.

Test: boots and VTS
Change-Id: I924cadce9a10a6e544f99ceba63aadc38ec431ac
diff --git a/graphics/mapper/2.0/default/Android.bp b/graphics/mapper/2.0/default/Android.bp
index 677d966..8874799 100644
--- a/graphics/mapper/2.0/default/Android.bp
+++ b/graphics/mapper/2.0/default/Android.bp
@@ -18,8 +18,10 @@
     defaults: ["hidl_defaults"],
     vendor: true,
     relative_install_path: "hw",
-    srcs: ["GrallocMapper.cpp", "Gralloc0Mapper.cpp", "Gralloc1Mapper.cpp"],
-    cppflags: ["-Wall", "-Wextra"],
+    srcs: ["passthrough.cpp"],
+    header_libs: [
+        "android.hardware.graphics.mapper@2.0-passthrough"
+    ],
     shared_libs: [
         "android.hardware.graphics.mapper@2.0",
         "libbase",
@@ -31,10 +33,5 @@
         "libsync",
         "libutils",
     ],
-}
-
-cc_library_headers {
-    name: "libgrallocmapperincludes",
-    vendor: true,
-    export_include_dirs: ["."],
+    cflags: ["-DLOG_TAG=\"MapperHal\""],
 }