Remove ndk_platform backend. Use the ndk backend.

The ndk_platform backend will soon be deprecated because the ndk backend
can serve the same purpose. This is to eliminate the confusion about
having two variants (ndk and ndk_platform) for the same 'ndk' backend.

Bug: 161456198
Test: m
Change-Id: I87554ce86da0f862568c5aa84a21e6613655eb25
diff --git a/Android.bp b/Android.bp
index 466ba77..35f74bf 100644
--- a/Android.bp
+++ b/Android.bp
@@ -165,9 +165,9 @@
     },
     shared_libs: [
         "android.hardware.health.storage@1.0",
-        "android.hardware.health.storage-V1-ndk_platform",
-        "android.system.keystore2-V1-ndk_platform",
-        "android.security.maintenance-ndk_platform",
+        "android.hardware.health.storage-V1-ndk",
+        "android.system.keystore2-V1-ndk",
+        "android.security.maintenance-ndk",
         "libbinder_ndk",
         "libkeymint_support",
     ],
@@ -197,9 +197,9 @@
 
     shared_libs: [
         "android.hardware.health.storage@1.0",
-        "android.hardware.health.storage-V1-ndk_platform",
-        "android.system.keystore2-V1-ndk_platform",
-        "android.security.maintenance-ndk_platform",
+        "android.hardware.health.storage-V1-ndk",
+        "android.system.keystore2-V1-ndk",
+        "android.security.maintenance-ndk",
         "libbinder_ndk",
         "libkeymint_support",
     ],