Merge "Docs: add more detail to SurfaceTexture#getTimestamp" into pi-dev

     * Retrieve the timestamp associated with the texture image set by the most recent call to

     * updateTexImage.

     *

     * This timestamp is in nanoseconds, and is normally monotonically increasing. The timestamp

     * should be unaffected by time-of-day adjustments, and for a camera should be strictly

     * monotonic but for a MediaPlayer may be reset when the position is set.  The

     * specific meaning and zero point of the timestamp depends on the source providing images to

     * the SurfaceTexture. Unless otherwise specified by the image source, timestamps cannot

     * generally be compared across SurfaceTexture instances, or across multiple program

     * invocations. It is mostly useful for determining time offsets between subsequent frames.

     * <p>This timestamp is in nanoseconds, and is normally monotonically increasing. The timestamp

     * should be unaffected by time-of-day adjustments. The specific meaning and zero point of the

     * timestamp depends on the source providing images to the SurfaceTexture. Unless otherwise

     * specified by the image source, timestamps cannot generally be compared across SurfaceTexture

     * instances, or across multiple program invocations. It is mostly useful for determining time

     * offsets between subsequent frames.</p>

     *

     * <p>For camera sources, timestamps should be strictly monotonic. Timestamps from MediaPlayer

     * sources may be reset when the playback position is set. For EGL and Vulkan producers, the

     * timestamp is the desired present time set with the EGL_ANDROID_presentation_time or

     * VK_GOOGLE_display_timing extensions.</p>

     */

    public long getTimestamp() {