Avoid destroying Device separately

Bug: 27983025

Device should be destroyed inside the destructor of the associated
Context.

Change-Id: I921a89974e1174f837349a89aef9b03efa4882f5
(cherry picked from commit 4a70df58a32591429ec04902deac2b2210fb96c3)
diff --git a/rs/java/android/renderscript/RenderScript.java b/rs/java/android/renderscript/RenderScript.java
index 9beaba3..2650e5a 100644
--- a/rs/java/android/renderscript/RenderScript.java
+++ b/rs/java/android/renderscript/RenderScript.java
@@ -1031,7 +1031,6 @@
 
 
 
-    long     mDev;
     long     mContext;
     private boolean mDestroyed = false;
 
@@ -1426,8 +1425,8 @@
 
         RenderScript rs = new RenderScript(ctx);
 
-        rs.mDev = rs.nDeviceCreate();
-        rs.mContext = rs.nContextCreate(rs.mDev, flags, sdkVersion, ct.mID);
+        long device = rs.nDeviceCreate();
+        rs.mContext = rs.nContextCreate(device, flags, sdkVersion, ct.mID);
         rs.mContextType = ct;
         rs.mContextFlags = flags;
         rs.mContextSdkVersion = sdkVersion;
@@ -1635,9 +1634,6 @@
             }
 
             nContextDestroy();
-
-            nDeviceDestroy(mDev);
-            mDev = 0;
         }
     }
 
diff --git a/rs/java/android/renderscript/RenderScriptGL.java b/rs/java/android/renderscript/RenderScriptGL.java
index 6178994..be1f899 100644
--- a/rs/java/android/renderscript/RenderScriptGL.java
+++ b/rs/java/android/renderscript/RenderScriptGL.java
@@ -177,9 +177,9 @@
 
         mWidth = 0;
         mHeight = 0;
-        mDev = nDeviceCreate();
+        long device = nDeviceCreate();
         int dpi = ctx.getResources().getDisplayMetrics().densityDpi;
-        mContext = nContextCreateGL(mDev, 0, sdkVersion,
+        mContext = nContextCreateGL(device, 0, sdkVersion,
                                     mSurfaceConfig.mColorMin, mSurfaceConfig.mColorPref,
                                     mSurfaceConfig.mAlphaMin, mSurfaceConfig.mAlphaPref,
                                     mSurfaceConfig.mDepthMin, mSurfaceConfig.mDepthPref,