[SPARK-32074][BUILD][R] Update AppVeyor R version to 4.0.2

### What changes were proposed in this pull request?
R version 4.0.2 was released, see https://cran.r-project.org/doc/manuals/r-release/NEWS.html. This PR targets to upgrade R version in AppVeyor CI environment.

### Why are the changes needed?

To test the latest R versions before the release, and see if there are any regressions.

### Does this PR introduce any user-facing change?

No.

### How was this patch tested?

AppVeyor will test.

Closes apache#28909 from HyukjinKwon/SPARK-32074.

Authored-by: HyukjinKwon <[email protected]>
Signed-off-by: HyukjinKwon <[email protected]>

Author: HyukjinKwon

R/install-dev.bat

@@ -24,7 +24,13 @@ set SPARK_HOME=%~dp0..
 
 MKDIR %SPARK_HOME%\R\lib
 
-R.exe CMD INSTALL --library="%SPARK_HOME%\R\lib"  %SPARK_HOME%\R\pkg\
+rem When you pass the package path directly as an argument to R CMD INSTALL,
+rem it takes the path as 'C:\projects\spark\R\..\R\pkg"' as an example at
+rem R 4.0. To work around this, directly go to the directoy and install it.
+rem See also SPARK-32074
+pushd %SPARK_HOME%\R\pkg\
+R.exe CMD INSTALL --library="%SPARK_HOME%\R\lib" .
+popd
 
 rem Zip the SparkR package so that it can be distributed to worker nodes on YARN
 pushd %SPARK_HOME%\R\lib

dev/appveyor-install-dependencies.ps1

@@ -115,8 +115,8 @@ $env:Path += ";$env:HADOOP_HOME\bin"
 Pop-Location
 
 # ========================== R
-$rVer = "3.6.2"
-$rToolsVer = "4.0.0"
+$rVer = "4.0.2"
+$rToolsVer = "4.0.2"
 
 InstallR
 InstallRtools