envsetup: aospremote: Take .gitupstream into account

Adapt function for .gitupstream so we always get the correct
remote without needing to calculate the path manually.

Test: Run `aospremote` in `kernel/configs` repository.
Change-Id: Idcac37ded4a5b2d62d26dc01dd7d68039def6220

build/envsetup.sh

@@ -279,17 +279,23 @@ function aospremote()
         return 1
     fi
     git remote rm aosp 2> /dev/null
-    local PROJECT=$(pwd -P | sed -e "s#$ANDROID_BUILD_TOP\/##; s#-caf.*##; s#\/default##")
-    # Google moved the repo location in Oreo
-    if [ $PROJECT = "build/make" ]
-    then
-        PROJECT="build"
+
+    if [ -f ".gitupstream" ]; then
+        local REMOTE=$(cat .gitupstream | cut -d ' ' -f 1)
+        git remote add aosp ${REMOTE}
+    else
+        local PROJECT=$(pwd -P | sed -e "s#$ANDROID_BUILD_TOP\/##; s#-caf.*##; s#\/default##")
+        # Google moved the repo location in Oreo
+        if [ $PROJECT = "build/make" ]
+        then
+            PROJECT="build"
+        fi
+        if (echo $PROJECT | grep -qv "^device")
+        then
+            local PFX="platform/"
+        fi
+        git remote add aosp https://android.googlesource.com/$PFX$PROJECT
     fi
-    if (echo $PROJECT | grep -qv "^device")
-    then
-        local PFX="platform/"
-    fi
-    git remote add aosp https://android.googlesource.com/$PFX$PROJECT
     echo "Remote 'aosp' created"
 }