How to remove extra space around polar plot in manipulate? [duplicate]

Question

In Manipulate, PolarPlot adds lots of useless space around the exterior circular grid. Is there a way to remove that space, so the whole circular plot could take more space ? Here's a MWE showing the problem :

Manipulate[
    Show[
        PolarPlot[
        {LegendreP[n,Cos[theta]], (2n + 1)/2 LegendreP[n, Cos[theta]]^2 Sin[theta]},
        {theta, 0, 2 Pi},
        PlotStyle -> {Blue, Red},
        PolarGridLines -> Automatic,
        PolarAxes -> True,
        PolarTicks -> {"Degrees", Automatic},
        PolarAxesOrigin -> {0, 1}
    ],
    AspectRatio -> 1,
    ImageSize -> {600, 600}
    ],
    {{n, 1, "n"}, 0, 50, 1},
    ControlPlacement -> Bottom,
    FrameMargins -> None
]