Generic x86_64: Bump system image partition size to 1.75 GB.

BUG=b.android.com/201662

Change-Id: I3b13082d73a3e1c9f49cb9158d2423dc580a8c75
diff --git a/target/board/generic_x86_64/BoardConfig.mk b/target/board/generic_x86_64/BoardConfig.mk
index 214454e..553bec9 100755
--- a/target/board/generic_x86_64/BoardConfig.mk
+++ b/target/board/generic_x86_64/BoardConfig.mk
@@ -38,7 +38,7 @@
 USE_OPENGL_RENDERER := true
 
 TARGET_USERIMAGES_USE_EXT4 := true
-BOARD_SYSTEMIMAGE_PARTITION_SIZE := 1610612736
+BOARD_SYSTEMIMAGE_PARTITION_SIZE := 1879048192  # 1.75 GB
 BOARD_USERDATAIMAGE_PARTITION_SIZE := 576716800
 BOARD_CACHEIMAGE_PARTITION_SIZE := 69206016
 BOARD_CACHEIMAGE_FILE_SYSTEM_TYPE := ext4