Update release config and emulator files for Android S(API 31) Beta1

Bug: 185838357
Change-Id: I5a0f0aa1f49b8bd6e6a85462283bb2f7f3ad7776
diff --git a/sdk/build_tools_source.prop_template b/sdk/build_tools_source.prop_template
index b84ae2c..2ea175b 100644
--- a/sdk/build_tools_source.prop_template
+++ b/sdk/build_tools_source.prop_template
@@ -1,3 +1,3 @@
 Pkg.UserSrc=false
 #Pkg.Revision=${PLATFORM_SDK_VERSION}.0.0
-Pkg.Revision=31.0.0 rc3
+Pkg.Revision=31.0.0 rc4
diff --git a/sdk/platform_source.prop_template b/sdk/platform_source.prop_template
index 9dc99a0..ff513ff 100644
--- a/sdk/platform_source.prop_template
+++ b/sdk/platform_source.prop_template
@@ -2,7 +2,7 @@
 Pkg.UserSrc=false
 Platform.Version=${PLATFORM_VERSION}
 Platform.CodeName=
-Pkg.Revision=3
+Pkg.Revision=4
 AndroidVersion.ApiLevel=${PLATFORM_SDK_VERSION}
 AndroidVersion.CodeName=${PLATFORM_VERSION_CODENAME}
 Layoutlib.Api=15