fastbootd: Add commands for logical partitions.

This patch adds the following new commands to fastbootd:

    getvar is_logical:<partition>
    create-logical-logical-partition <partition> <size>
    delete-logical-partition <partition>
    resize-logicallogical-partition <partition> <size>

All of these commands operate on logical partitions only, and require a
properly configured "super" partition to operate.

Bug: 78793464
Test: fastboot create-logical-partition example 4096
      fastboot create-logical-partition example 4096 returns error
      fastboot getvar is-logical:example returns "yes"
      fastboot getvar partition-size:example returns "1000"
      fastboot resize-logicalpartition example 8000
      fastboot getvar partition-size:example returns "2000"
      fastboot delete-logical-partition example
      fastboot getvar is-logical:example returns error
      fastboot getvar is-logical:system_a returns "no"

Change-Id: Iff323eabcf5c559fa04c7c92574650b01803eb1f
diff --git a/fastboot/constants.h b/fastboot/constants.h
index fa17070..b780ba5 100644
--- a/fastboot/constants.h
+++ b/fastboot/constants.h
@@ -30,6 +30,9 @@
 #define FB_CMD_REBOOT_RECOVERY "reboot-recovery"
 #define FB_CMD_REBOOT_FASTBOOT "reboot-fastboot"
 #define FB_CMD_POWERDOWN "powerdown"
+#define FB_CMD_CREATE_PARTITION "create-logical-partition"
+#define FB_CMD_DELETE_PARTITION "delete-logical-partition"
+#define FB_CMD_RESIZE_PARTITION "resize-logical-partition"
 
 #define RESPONSE_OKAY "OKAY"
 #define RESPONSE_FAIL "FAIL"
@@ -53,3 +56,4 @@
 #define FB_VAR_PARTITION_SIZE "partition-size"
 #define FB_VAR_SLOT_SUCCESSFUL "slot-successful"
 #define FB_VAR_SLOT_UNBOOTABLE "slot-unbootable"
+#define FB_VAR_IS_LOGICAL "is-logical"