Make the RRectEffect's screen coords be Float4 (rather than Half4)
Make the RRectEffect's screen coords be Float4 (rather than Half4)

For large screens Half4 can have insufficient precision to effectively address all of screen space.

This was originally found and fixed in https://android-review.googlesource.com/c/platform/external/skia/+/859297 (fix CtsViewTestCases).

Bug: b/122105577
Change-Id: I7a18cd9f8ea1fcf2340e456597760ca189d404e2
Reviewed-on: https://skia-review.googlesource.com/c/180926
Commit-Queue: Robert Phillips <95e8ac5504948c7bf91b22c16a8dbb7ae7c66bfd@google.com>
Reviewed-by: Greg Daniel <39df0a804564ccb6cf75f18db79653821f37c1c5@google.com>

google/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,google/skia,google/skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,rubenvb/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,aosp-mirror/platform_external_skia,HalCanary/skia-hc,HalCanary/skia-hc,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,rubenvb/skia,google/skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia,google/skia,google/skia,google/skia,HalCanary/skia-hc,HalCanary/skia-hc,HalCanary/skia-hc,google/skia,rubenvb/skia,rubenvb/skia,HalCanary/skia-hc,rubenvb/skia,aosp-mirror/platform_external_skia,rubenvb/skia,Hikari-no-Tenshi/android_external_skia,google/skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,Hikari-no-Tenshi/android_external_skia,Hikari-no-Tenshi/android_external_skia,aosp-mirror/platform_external_skia,aosp-mirror/platform_external_skia