Set default size for 32-bit GSI to 1 GB

The previous size for 32-bit GSI (906 MB) is not enough for x86 GSI.
Increase it to 1 GB (1024 MB). If some other arch, say arm, wants to
use a smaller size, it can overwrite the default in its BoardConfig.mk.

Bug: 65437122
Test: lunch aosp_x86_a; make -j; lunch aosp_arm_a; make -j
Change-Id: I092966f0a0a327b1080ee10782960c6ccf44d8ee
diff --git a/target/board/generic_arm_a/BoardConfig.mk b/target/board/generic_arm_a/BoardConfig.mk
index 57a5196..e3a6707 100644
--- a/target/board/generic_arm_a/BoardConfig.mk
+++ b/target/board/generic_arm_a/BoardConfig.mk
@@ -16,6 +16,9 @@
 
 include build/make/target/board/treble_common_32.mk
 
+# Overwrite the setting in treble_common_32.mk for non-A/B arm GSI
+BOARD_SYSTEMIMAGE_PARTITION_SIZE := 950009856
+
 TARGET_ARCH := arm
 TARGET_ARCH_VARIANT := armv7-a-neon
 TARGET_CPU_ABI := armeabi-v7a
diff --git a/target/board/treble_common_32.mk b/target/board/treble_common_32.mk
index 2c3447b..dbe0899 100644
--- a/target/board/treble_common_32.mk
+++ b/target/board/treble_common_32.mk
@@ -16,5 +16,6 @@
 
 include build/make/target/board/treble_common.mk
 
-# Partition size is default 906MB for 32 bits projects
-BOARD_SYSTEMIMAGE_PARTITION_SIZE := 950009856
+# Partition size defaults to 1 GB (1024 MB) for 32-bit products. It can
+# be overwritten in specific BoardConfig.mk, if so desired.
+BOARD_SYSTEMIMAGE_PARTITION_SIZE := 1073741824