Upon expanding, expand just enough so the header shows.

This issue only happens when there is a lot of private space apps that scrolling to the bottom
will not sure the private space header.

Formula to calculate how many rows to scroll to =
	(appListHeight - privateHeaderHeight - headerProtectionHeight) / cellHeight.

bug: 299294792
Test:
manually - https://screenshot.googleplex.com/76UJPT2Jnpnp2Ab
before: it just scrolls all the way to the bottom
after: https://drive.google.com/file/d/1AbprxFm1RWTQKvpt7M4khbUfc1o6-XGF/view?usp=sharing
after PHONE WITH TABS:
2x2- https://drive.google.com/file/d/1SLPsWPHenCuZuisiS7HeEy5JwtNPeONs/view?usp=sharing
3x3- https://drive.google.com/file/d/1SK82jeNZMzFJK2odIuHnfTNLYfppne83/view?usp=sharing
4x4- https://drive.google.com/file/d/1T7EhFRq2tDv2zYIvs_FMsTKcFZXwGUaD/view?usp=sharing
4x5- https://drive.google.com/file/d/1SMUPuKjO1Yg36U6P6cDOb6dTkHn6Bh7D/view?usp=sharing
5x5- https://drive.google.com/file/d/1SJCQn1O_Yq5P7C__VUfZHc5I67CEdIpb/view?usp=sharing

AFTER PHONE NO TABS:
2x2: https://drive.google.com/file/d/1THU2xrAIt0hTmN5_GwBrgN9Lqj-W4Kfr/view?usp=sharing
3x3: https://drive.google.com/file/d/1TPTUx7PcHW3GsVwVAg_L5rCcn0QYoiY2/view?usp=sharing
4x4: https://drive.google.com/file/d/1TWVWpAX6bZp_JfFKtmXYO0askl4e5qKO/view?usp=sharing
4x5: https://drive.google.com/file/d/1TDJK-swmY3Y3C4ARH_2eljqUkBGEnD3e/view?usp=sharing
5x5- https://drive.google.com/file/d/1TBJtAynwvZrGyOc-29f637wyrJZpMXBJ/view?usp=sharing

Tablet:
landscape: https://drive.google.com/file/d/1SfyPdoUnCV7e7BWLnpxXWN2HiBOQkRo2/view?usp=sharing
portrait: https://drive.google.com/file/d/1SgZq0iE9WMvIFtc8mBb577nYlS9jBa_g/view?usp=sharing
Flag: ACONFIG com.android.launcher3.Flags.private_space_animation TRUNKFOOD

Change-Id: If70df1299572f8f2edc6376dd2a6df5d74287264