Remove minLayer and maxLayer from display screenshot.

When taking a full display screenshot, there's no longer a need for min
and max layer. Instead, the entire display will be screenshotted. If
only some layers should be screenshotted, then use the captureLayers method
instead.

Also, condensed the methods so there is only one screenshot method for
displays that returns a GraphicBuffer. SurfaceControl can then convert
it to the desired format, like Bitmap or Surface.

Test: Rotation, adb shell screencap, power + volume down, bugreport.
Change-Id: Ia5a293e89d2cf3811fd06ffcbafeee389a32840e
diff --git a/cmds/screencap/screencap.cpp b/cmds/screencap/screencap.cpp
index b11e843..11029e7 100644
--- a/cmds/screencap/screencap.cpp
+++ b/cmds/screencap/screencap.cpp
@@ -198,8 +198,7 @@
 
     sp<GraphicBuffer> outBuffer;
     status_t result = ScreenshotClient::capture(display, Rect(), 0 /* reqWidth */,
-            0 /* reqHeight */, INT32_MIN, INT32_MAX, /* all layers */ false, captureOrientation,
-            &outBuffer);
+            0 /* reqHeight */, false, captureOrientation, &outBuffer);
     if (result != NO_ERROR) {
         close(fd);
         return 1;