Expose colors for disabled state

[Kato Robert Berti]

Expose colors for when the bar is disabled.
mBarColor = DEFAULT_BAR_COLOR; setConnectingLineColor(DEFAULT_BAR_COLOR); mThumbColor = DEFAULT_BAR_COLOR; mThumbColorLeft = DEFAULT_BAR_COLOR; mThumbColorRight = DEFAULT_BAR_COLOR; mThumbBoundaryColor = DEFAULT_BAR_COLOR; mTickDefaultColor = DEFAULT_BAR_COLOR; setTickColors(DEFAULT_BAR_COLOR); mTickLabelColor = DEFAULT_BAR_COLOR; mTickLabelSelectedColor = DEFAULT_BAR_COLOR;